Functions and Structure Triple Dimension Array
In this section, you are going to learn
What are the calling conventions of structure triple dimension array ?
Call by Value
Call by Reference
Revisit Basics : Basics of Structure Triple Dimension Array
Topics in this section,
struct ABC {
type1 member1;
type2 member2;
type3 member3;
etc.,
};
struct ABC array_name[Block][Row][Column];
Consider a structure triple dimension array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Let us answer few basic questions in this array
If fun(x) is the function call, then fun(typeof(x)) is the prototype / definition
Function Call |
Function Definition |
Observations |
|---|---|---|
fun(x[0][0][0]) |
void fun(struct ABC x) {} |
|
fun(x[1][0][0]) |
void fun(struct ABC x) {} |
|
fun(&x[0][0][0]) |
void fun(struct ABC *p) {} |
|
fun(&x[1][0][0]) |
void fun(struct ABC *p) {} |
|
fun(x[0][0]) |
void fun(struct ABC *p) {} |
|
fun(x[1][0]) |
void fun(struct ABC *p) {} |
|
fun(&x[0][0]) |
void fun(struct ABC (*p)[4]) {} |
|
fun(&x[1][0]) |
void fun(struct ABC (*p)[4]) {} |
|
fun(**x) |
void fun(struct ABC *p) {} |
|
fun(*(*(x + 1) + 0)) |
void fun(struct ABC *p) {} |
|
fun(x[0]) |
void fun(struct ABC (*p)[4]) {} |
|
fun(x[1]) |
void fun(struct ABC (*p)[4]) {} |
|
fun(&x[0]) |
void fun(struct ABC (*p)[3][4]) {} |
|
fun(&x[1]) |
void fun(struct ABC (*p)[3][4]) {} |
|
fun(*x) |
void fun(struct ABC (*p)[4]) {} |
|
fun(*(x + 1)) |
void fun(struct ABC (*p)[4]) {} |
|
fun(x) |
void fun(struct ABC (*p)[3][4]) {} |
|
fun(x + 1) |
void fun(struct ABC (*p)[3][4]) {} |
|
fun(&x) |
void fun(struct ABC (*p)[2][3][4]) {} |
|
Let us understand the reason behind above prototypes !
If Declaration has THREE dereference operators, and
Expression has THREE dereference operators * * *, and
Expression does not have
&then it is call by value
If Declaration has THREE dereference operators, and
Expression has THREE dereference operators * * [ ], and
Expression does not have
&then it is call by value
If Declaration has THREE dereference operators, and
Expression has THREE dereference operators * [ ] [ ], and
Expression does not have
&then it is call by value
If Declaration has THREE dereference operators, and
Expression has THREE dereference operators [] [] [], and
Expression does not have
&then it is call by value
Let us look at examples
Step 1 : Consider an array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Condition 1 : Declaration has THREE dereference operators [ ], [ ] and [ ]
Step 2 : Consider an expression
x[1][1][1]
Condition 2 : Expression has THREE dereference operators [ ], [ ] and [ ]
Note : [ ] and * are dereference operators
Condition 3 : Expression DOES NOT have & operator
Hence x[1][1][1] is Call By Value
Step 1 : Consider an array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Condition 1 : Declaration has THREE dereference operators [ ], [ ] and [ ]
Step 2 : Consider an expression
***x
Condition 2 : Expression has THREE dereference operators *, * and *
Note : [ ] and * are dereference operators
Condition 3 : Expression DOES NOT have & operator
Hence ***x is Call By Value
If Declaration has THREE dereference operators, and
Expression has THREE dereference operators * * * OR * * [] OR * [] [] OR [] [] [] and
Expression has &
then it is call by reference
Example : &x[0][0][0], &x[1][2][3]
If Declaration has THREE dereference operators, and
Expression has TWO dereference operator * * OR [] [] OR * []
then it is call by reference
Example : x[0][0]
If Declaration has THREE dereference operators, and
Expression has ONE dereference operators, * OR [ ]
then it is call by reference
Example : x[0]
If Declaration has THREE dereference operators, and
Expression has ZERO dereference operators
then it is call by reference
Example : x
Step 1 : Consider an array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Condition 1 : Declaration has THREE dereference operators [ ] [ ] and [ ]
Step 2 : Consider an expression
&x[1][1][1]
Condition 2 : Expression has THREE dereference operators [ ] [ ] and [ ]
Note : [ ] and * are dereference operators
Condition 3 : Expression has & operator
Hence &x[1][1][1] is Call By Reference
Step 1 : Consider an array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Condition 1 : Declaration has THREE dereference operators [ ] [ ] and [ ]
Step 2 : Consider an expression
x[1]
Condition 2 : Expression has ONE dereference operator
Note : [ ] and * are dereference operators
Condition 3 : Expression DOES NOT have & operator
Hence x[1] is Call By Reference
Let us look at examples of Call by Value
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
Step 2 : Pass x[0][0][0], x[1][0][0] to a function
fun
fun(x[0][0][0]);
fun(x[1][0][0]);
Step 3 : Define function
fun
void fun(struct ABC y)
{
y.a = 777;
y.b = 888;
y.c = 999;
}
Step 4 : Note that it is call by Value for below reason
Condition 1 : Declaration has THREE dereference operators [ ] [ ] and [ ]
Condition 2 : Expression has THREE dereference operators [ ] [ ] and [ ]
Condition 3 : Expression DOES NOT have & operator
Means changing value of structure inside function DOES NOT affect value of structure in Caller !
See full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC y)
{
y.a = 777;
y.b = 888;
y.c = 999;
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Value -----\n");
printf("x[0][0][0].a = %d\n", x[0][0][0].a);
printf("x[1][0][0].a = %d\n", x[1][0][0].a);
fun(x[0][0][0]);
fun(x[1][0][0]);
printf("----- After Call By Value -----\n");
printf("x[0][0][0].a = %d\n", x[0][0][0].a);
printf("x[1][0][0].a = %d\n", x[1][0][0].a);
return 0;
}
Output is as below
----- Before Call By Value -----
x[0][0][0].a = 1
x[1][0][0].a = 37
----- After Call By Value -----
x[0][0][0].a = 1
x[1][0][0].a = 37
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Step 2 : Pass ***x, *(*(*(x + 1) + 0) + 0) to a function
fun
fun( ***x );
fun( *(*(*(x + 1) + 0) + 0) );
Step 3 : Define function
fun
void fun(struct ABC y)
{
y.a = 777;
y.b = 888;
y.c = 999;
}
Step 4 : Note that it is call by Value for below reason
Condition 1 : Declaration has THREE dereference operators [ ] [ ] and [ ]
Condition 2 : Expression has THREE dereference operators * * and *
Condition 3 : Expression DOES NOT have & operator
Means changing value of structure inside function DOES NOT affect value of structure in Caller !
See full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC y)
{
y.a = 777;
y.b = 888;
y.c = 999;
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Value -----\n");
printf(" (***x).a = %d\n", (***x).a );
printf(" (*(*(*(x + 1) + 0) + 0)).a = %d\n", (*(*(*(x + 1) + 0) + 0)).a );
fun( ***x );
fun( *(*(*(x + 1) + 0) + 0) );
printf("----- After Call By Value -----\n");
printf(" (***x).a = %d\n", (***x).a );
printf(" (*(*(*(x + 1) + 0) + 0)).a = %d\n", (*(*(*(x + 1) + 0) + 0)).a );
return 0;
}
Output is as below
----- Before Call By Value -----
(***x).a = 1
(*(*(*(x + 1) + 0) + 0)).a = 37
----- After Call By Value -----
(***x).a = 1
(*(*(*(x + 1) + 0) + 0)).a = 37
Let us look at examples of Call by Reference
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
There are 6 single dimension arrays in struct ABC x[2][3][4]
x[0][0]
x[0][1]
x[0][2]
x[1][0]
x[1][1]
x[1][2]
Step 2.1 : Method 1 : Pass x[0][0], x[1][0] to a function
fun
fun( x[0][0] );
fun( x[1][0] );
Step 2.2 : Method 2 : Pass &x[0][0][0], &x[1][0][0] to a function
fun
fun( &x[0][0][0] );
fun( &x[1][0][0] );
Step 2.3 : Method 3 : Pass **x, *(*(x + 1) + 0) to a function
fun
fun( **x );
fun( *(*(x + 1) + 0) );
Step 3.1 : Define function
fun
void fun(struct ABC *ptr)
{
}
Step 3.2 : Note that it is call by Reference. Means contents of single dimension array can be changed inside function
fun
void fun(struct ABC *ptr)
{
// 1. Address of single dimension array is passed from caller
// 2. We know that size of each single dimension array is 4 structures
// 3. Hence, we can change access and change values of 4 structures in this function
int data = 99;
for (int i = 0; i < 4; i++)
{
ptr[i].a = data++;
ptr[i].b = data++;
ptr[i].c = data++;
}
}
See full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC *ptr)
{
// 1. Address of single dimension array is passed from caller
// 2. We know that size of each single dimension array is 4 structures
// 3. Hence, we can change access and change values of 4 structures in this function
int data = 99;
for (int i = 0; i < 4; i++)
{
ptr[i].a = data++;
ptr[i].b = data++;
ptr[i].c = data++;
}
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Reference -----\n");
for (int i = 0; i < 4; i++)
{
printf("x[0][0][%d].a = %d ", i, x[0][0][i].a );
printf("x[0][0][%d].b = %d ", i, x[0][0][i].b );
printf("x[0][0][%d].c = %d ", i, x[0][0][i].c );
printf("\n");
}
printf("\n");
for (int i = 0; i < 4; i++)
{
printf("x[1][0][%d].a = %d ", i, x[1][0][i].a );
printf("x[1][0][%d].b = %d ", i, x[1][0][i].b );
printf("x[1][0][%d].c = %d ", i, x[1][0][i].c );
printf("\n");
}
// Method 1 : Access Single dimension arrays
fun( x[0][0] );
fun( x[1][0] );
// Method 2 : Access Single dimension arrays
fun( &x[0][0][0] );
fun( &x[1][0][0] );
// Method 3 : Access Single dimension arrays
fun( **x );
fun( *(*(x + 1) + 0) );
printf("----- After Call By Reference -----\n");
for (int i = 0; i < 4; i++)
{
printf("x[0][0][%d].a = %d ", i, x[0][0][i].a );
printf("x[0][0][%d].b = %d ", i, x[0][0][i].b );
printf("x[0][0][%d].c = %d ", i, x[0][0][i].c );
printf("\n");
}
printf("\n");
for (int i = 0; i < 4; i++)
{
printf("x[1][0][%d].a = %d ", i, x[1][0][i].a );
printf("x[1][0][%d].b = %d ", i, x[1][0][i].b );
printf("x[1][0][%d].c = %d ", i, x[1][0][i].c );
printf("\n");
}
return 0;
}
Output is as below
----- Before Call By Reference -----
x[0][0][0].a = 1 x[0][0][0].b = 2 x[0][0][0].c = 3
x[0][0][1].a = 4 x[0][0][1].b = 5 x[0][0][1].c = 6
x[0][0][2].a = 7 x[0][0][2].b = 8 x[0][0][2].c = 9
x[0][0][3].a = 10 x[0][0][3].b = 11 x[0][0][3].c = 12
x[1][0][0].a = 37 x[1][0][0].b = 38 x[1][0][0].c = 39
x[1][0][1].a = 40 x[1][0][1].b = 41 x[1][0][1].c = 42
x[1][0][2].a = 43 x[1][0][2].b = 44 x[1][0][2].c = 45
x[1][0][3].a = 46 x[1][0][3].b = 47 x[1][0][3].c = 48
----- After Call By Reference -----
x[0][0][0].a = 99 x[0][0][0].b = 100 x[0][0][0].c = 101
x[0][0][1].a = 102 x[0][0][1].b = 103 x[0][0][1].c = 104
x[0][0][2].a = 105 x[0][0][2].b = 106 x[0][0][2].c = 107
x[0][0][3].a = 108 x[0][0][3].b = 109 x[0][0][3].c = 110
x[1][0][0].a = 99 x[1][0][0].b = 100 x[1][0][0].c = 101
x[1][0][1].a = 102 x[1][0][1].b = 103 x[1][0][1].c = 104
x[1][0][2].a = 105 x[1][0][2].b = 106 x[1][0][2].c = 107
x[1][0][3].a = 108 x[1][0][3].b = 109 x[1][0][3].c = 110
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
There are 6 single dimension arrays in struct ABC x[2][3][4]
x[0][0]
x[0][1]
x[0][2]
x[1][0]
x[1][1]
x[1][2]
Address of single dimension arrays is simply
&x[0][0]
&x[0][1]
&x[0][2]
&x[1][0]
&x[1][1]
&x[1][2]
Step 2.1 : Method 1 : Pass address of single dimension arrays to a function
fun
fun( &x[0][0] );
fun( &x[1][0] );
Step 2.2 : Method 2 : Pass address of single dimension arrays to a function
fun
fun( x[0] );
fun( x[1] );
Step 2.3 : Method 2 : Pass address of single dimension arrays to a function
fun
fun( *x );
fun( *(x + 1) );
Step 3.1 : Define the function
fun
void fun(struct ABC (*ptr)[4] )
{
}
Step 3.2 : Define the function
funto change the contents of single dimension array structure by structure
void fun(struct ABC (*ptr)[4] )
{
(*ptr)[0].a = 66; (*ptr)[0].b = 66; (*ptr)[0].c = 66;
(*ptr)[1].a = 77; (*ptr)[1].b = 77; (*ptr)[1].c = 77;
(*ptr)[2].a = 88; (*ptr)[2].b = 88; (*ptr)[2].c = 88;
(*ptr)[3].a = 99; (*ptr)[3].b = 99; (*ptr)[3].c = 99;
}
See full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC (*ptr)[4] )
{
(*ptr)[0].a = 66; (*ptr)[0].b = 66; (*ptr)[0].c = 66;
(*ptr)[1].a = 77; (*ptr)[1].b = 77; (*ptr)[1].c = 77;
(*ptr)[2].a = 88; (*ptr)[2].b = 88; (*ptr)[2].c = 88;
(*ptr)[3].a = 99; (*ptr)[3].b = 99; (*ptr)[3].c = 99;
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Reference -----\n");
for (int i = 0; i < 4; i++)
{
printf("x[0][0][%d].a = %d ", i, x[0][0][i].a );
printf("x[0][0][%d].b = %d ", i, x[0][0][i].b );
printf("x[0][0][%d].c = %d ", i, x[0][0][i].c );
printf("\n");
}
printf("\n");
for (int i = 0; i < 4; i++)
{
printf("x[1][0][%d].a = %d ", i, x[1][0][i].a );
printf("x[1][0][%d].b = %d ", i, x[1][0][i].b );
printf("x[1][0][%d].c = %d ", i, x[1][0][i].c );
printf("\n");
}
// Method 1 : Access Single dimension arrays
fun( &x[0][0] );
fun( &x[1][0] );
// Method 2 : Access Single dimension arrays
fun( x[0] );
fun( x[1] );
// Method 3 : Access Single dimension arrays
fun( *x );
fun( *(x + 1) );
printf("----- After Call By Reference -----\n");
for (int i = 0; i < 4; i++)
{
printf("x[0][0][%d].a = %d ", i, x[0][0][i].a );
printf("x[0][0][%d].b = %d ", i, x[0][0][i].b );
printf("x[0][0][%d].c = %d ", i, x[0][0][i].c );
printf("\n");
}
printf("\n");
for (int i = 0; i < 4; i++)
{
printf("x[1][0][%d].a = %d ", i, x[1][0][i].a );
printf("x[1][0][%d].b = %d ", i, x[1][0][i].b );
printf("x[1][0][%d].c = %d ", i, x[1][0][i].c );
printf("\n");
}
return 0;
}
Output is as below
----- Before Call By Reference -----
x[0][0][0].a = 1 x[0][0][0].b = 2 x[0][0][0].c = 3
x[0][0][1].a = 4 x[0][0][1].b = 5 x[0][0][1].c = 6
x[0][0][2].a = 7 x[0][0][2].b = 8 x[0][0][2].c = 9
x[0][0][3].a = 10 x[0][0][3].b = 11 x[0][0][3].c = 12
x[1][0][0].a = 37 x[1][0][0].b = 38 x[1][0][0].c = 39
x[1][0][1].a = 40 x[1][0][1].b = 41 x[1][0][1].c = 42
x[1][0][2].a = 43 x[1][0][2].b = 44 x[1][0][2].c = 45
x[1][0][3].a = 46 x[1][0][3].b = 47 x[1][0][3].c = 48
----- After Call By Reference -----
x[0][0][0].a = 66 x[0][0][0].b = 66 x[0][0][0].c = 66
x[0][0][1].a = 77 x[0][0][1].b = 77 x[0][0][1].c = 77
x[0][0][2].a = 88 x[0][0][2].b = 88 x[0][0][2].c = 88
x[0][0][3].a = 99 x[0][0][3].b = 99 x[0][0][3].c = 99
x[1][0][0].a = 66 x[1][0][0].b = 66 x[1][0][0].c = 66
x[1][0][1].a = 77 x[1][0][1].b = 77 x[1][0][1].c = 77
x[1][0][2].a = 88 x[1][0][2].b = 88 x[1][0][2].c = 88
x[1][0][3].a = 99 x[1][0][3].b = 99 x[1][0][3].c = 99
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Step 2 : Pass Double dimension array to function
fun
fun(x[1]);
Step 3.1 : Define function
fun
void fun(struct ABC (*ptr)[4])
{
}
Step 3.2 : Access and Change structures inside function
fun
void fun(struct ABC (*ptr)[4])
{
// 1. There are 3 single dimension arrays in one double dimension array
// 2. Each single dimension array has 4 structure objects
// 3. In total, 12 structures can be accessed and changed in this function
int data = 66;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
ptr[0][j].a = data++;
ptr[0][j].b = data++;
ptr[0][j].c = data++;
}
ptr++;
}
}
Step 4 : See the full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC (*ptr)[4])
{
// 1. There are 3 single dimension arrays in one double dimension array
// 2. Each single dimension array has 4 structure objects
// 3. In total, 12 structures can be accessed and changed in this function
int data = 66;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
ptr[0][j].a = data++;
ptr[0][j].b = data++;
ptr[0][j].c = data++;
}
ptr++;
}
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Reference -----\n");
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
printf("x[1][%d][%d].a = %d ", i, j, x[1][i][j].a);
printf("x[1][%d][%d].b = %d ", i, j, x[1][i][j].b);
printf("x[1][%d][%d].c = %d ", i, j, x[1][i][j].c);
printf("\n");
}
printf("\n");
}
fun(x[1]);
printf("----- After Call By Reference -----\n");
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
printf("x[1][%d][%d].a = %d ", i, j, x[1][i][j].a);
printf("x[1][%d][%d].b = %d ", i, j, x[1][i][j].b);
printf("x[1][%d][%d].c = %d ", i, j, x[1][i][j].c);
printf("\n");
}
printf("\n");
}
return 0;
}
Step 5 : Output is as below
----- Before Call By Reference -----
x[1][0][0].a = 37 x[1][0][0].b = 38 x[1][0][0].c = 39
x[1][0][1].a = 40 x[1][0][1].b = 41 x[1][0][1].c = 42
x[1][0][2].a = 43 x[1][0][2].b = 44 x[1][0][2].c = 45
x[1][0][3].a = 46 x[1][0][3].b = 47 x[1][0][3].c = 48
x[1][1][0].a = 49 x[1][1][0].b = 50 x[1][1][0].c = 51
x[1][1][1].a = 52 x[1][1][1].b = 53 x[1][1][1].c = 54
x[1][1][2].a = 55 x[1][1][2].b = 56 x[1][1][2].c = 57
x[1][1][3].a = 58 x[1][1][3].b = 59 x[1][1][3].c = 60
x[1][2][0].a = 61 x[1][2][0].b = 62 x[1][2][0].c = 63
x[1][2][1].a = 64 x[1][2][1].b = 65 x[1][2][1].c = 66
x[1][2][2].a = 67 x[1][2][2].b = 68 x[1][2][2].c = 69
x[1][2][3].a = 70 x[1][2][3].b = 71 x[1][2][3].c = 72
----- After Call By Reference -----
x[1][0][0].a = 66 x[1][0][0].b = 67 x[1][0][0].c = 68
x[1][0][1].a = 69 x[1][0][1].b = 70 x[1][0][1].c = 71
x[1][0][2].a = 72 x[1][0][2].b = 73 x[1][0][2].c = 74
x[1][0][3].a = 75 x[1][0][3].b = 76 x[1][0][3].c = 77
x[1][1][0].a = 78 x[1][1][0].b = 79 x[1][1][0].c = 80
x[1][1][1].a = 81 x[1][1][1].b = 82 x[1][1][1].c = 83
x[1][1][2].a = 84 x[1][1][2].b = 85 x[1][1][2].c = 86
x[1][1][3].a = 87 x[1][1][3].b = 88 x[1][1][3].c = 89
x[1][2][0].a = 90 x[1][2][0].b = 91 x[1][2][0].c = 92
x[1][2][1].a = 93 x[1][2][1].b = 94 x[1][2][1].c = 95
x[1][2][2].a = 96 x[1][2][2].b = 97 x[1][2][2].c = 98
x[1][2][3].a = 99 x[1][2][3].b = 100 x[1][2][3].c = 101
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Step 2 : Pass Address of Double dimension array to function
fun
fun(&x[1]);
Step 3.1 : Define function
fun
void fun(struct ABC (*ptr)[3][4])
{
}
Step 3.2 : Access and Change structures inside function
fun
void fun(struct ABC (*ptr)[3][4])
{
int data = 666;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
(*ptr)[i][j].a = data++;
(*ptr)[i][j].b = data++;
(*ptr)[i][j].c = data++;
}
}
}
Step 4 : See the full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC (*ptr)[3][4])
{
int data = 666;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
(*ptr)[i][j].a = data++;
(*ptr)[i][j].b = data++;
(*ptr)[i][j].c = data++;
}
}
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Reference -----\n");
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
printf("x[1][%d][%d].a = %d ", i, j, x[1][i][j].a);
printf("x[1][%d][%d].b = %d ", i, j, x[1][i][j].b);
printf("x[1][%d][%d].c = %d ", i, j, x[1][i][j].c);
printf("\n");
}
printf("\n");
}
fun(&x[1]);
printf("----- After Call By Reference -----\n");
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 4; j++)
{
printf("x[1][%d][%d].a = %d ", i, j, x[1][i][j].a);
printf("x[1][%d][%d].b = %d ", i, j, x[1][i][j].b);
printf("x[1][%d][%d].c = %d ", i, j, x[1][i][j].c);
printf("\n");
}
printf("\n");
}
return 0;
}
Step 5 : Output is as below
----- Before Call By Reference -----
x[1][0][0].a = 37 x[1][0][0].b = 38 x[1][0][0].c = 39
x[1][0][1].a = 40 x[1][0][1].b = 41 x[1][0][1].c = 42
x[1][0][2].a = 43 x[1][0][2].b = 44 x[1][0][2].c = 45
x[1][0][3].a = 46 x[1][0][3].b = 47 x[1][0][3].c = 48
x[1][1][0].a = 49 x[1][1][0].b = 50 x[1][1][0].c = 51
x[1][1][1].a = 52 x[1][1][1].b = 53 x[1][1][1].c = 54
x[1][1][2].a = 55 x[1][1][2].b = 56 x[1][1][2].c = 57
x[1][1][3].a = 58 x[1][1][3].b = 59 x[1][1][3].c = 60
x[1][2][0].a = 61 x[1][2][0].b = 62 x[1][2][0].c = 63
x[1][2][1].a = 64 x[1][2][1].b = 65 x[1][2][1].c = 66
x[1][2][2].a = 67 x[1][2][2].b = 68 x[1][2][2].c = 69
x[1][2][3].a = 70 x[1][2][3].b = 71 x[1][2][3].c = 72
----- After Call By Reference -----
x[1][0][0].a = 666 x[1][0][0].b = 667 x[1][0][0].c = 668
x[1][0][1].a = 669 x[1][0][1].b = 670 x[1][0][1].c = 671
x[1][0][2].a = 672 x[1][0][2].b = 673 x[1][0][2].c = 674
x[1][0][3].a = 675 x[1][0][3].b = 676 x[1][0][3].c = 677
x[1][1][0].a = 678 x[1][1][0].b = 679 x[1][1][0].c = 680
x[1][1][1].a = 681 x[1][1][1].b = 682 x[1][1][1].c = 683
x[1][1][2].a = 684 x[1][1][2].b = 685 x[1][1][2].c = 686
x[1][1][3].a = 687 x[1][1][3].b = 688 x[1][1][3].c = 689
x[1][2][0].a = 690 x[1][2][0].b = 691 x[1][2][0].c = 692
x[1][2][1].a = 693 x[1][2][1].b = 694 x[1][2][1].c = 695
x[1][2][2].a = 696 x[1][2][2].b = 697 x[1][2][2].c = 698
x[1][2][3].a = 699 x[1][2][3].b = 700 x[1][2][3].c = 701
Step 1 : Consider a THREE dimensional array
struct ABC {
int a;
int b;
int c;
};
struct ABC x[2][3][4];
Step 2 : Pass Address of Triple Dimension array to a function
fun(&x);
Step 3.1 : Define function
fun
void fun(struct ABC (*ptr)[2][3][4] )
{
}
Step 3.2 : Access and change individual structures inside function
fun
int data = 666;
for(int i = 0; i < 2; i++)
{
for(int j = 0; j < 3; j++)
{
for(int k = 0; k < 4; k++)
{
(*ptr)[i][j][k].a = data++;
(*ptr)[i][j][k].b = data++;
(*ptr)[i][j][k].c = data++;
}
}
}
See full program below
#include <stdio.h>
struct ABC {
int a;
int b;
int c;
};
void fun(struct ABC (*ptr)[2][3][4] )
{
//Access and change individual structures
int data = 666;
for(int i = 0; i < 2; i++)
{
for(int j = 0; j < 3; j++)
{
for(int k = 0; k < 4; k++)
{
(*ptr)[i][j][k].a = data++;
(*ptr)[i][j][k].b = data++;
(*ptr)[i][j][k].c = data++;
}
}
}
}
int main(void)
{
struct ABC x[2][3][4] = {
{
{
{.a = 1, .b = 2, .c = 3},
{.a = 4, .b = 5, .c = 6},
{.a = 7, .b = 8, .c = 9},
{.a = 10, .b = 11, .c = 12},
},
{
{.a = 13, .b = 14, .c = 15},
{.a = 16, .b = 17, .c = 18},
{.a = 19, .b = 20, .c = 21},
{.a = 22, .b = 23, .c = 24},
},
{
{.a = 25, .b = 26, .c = 27},
{.a = 28, .b = 29, .c = 30},
{.a = 31, .b = 32, .c = 33},
{.a = 34, .b = 35, .c = 36},
},
},
{
{
{.a = 37, .b = 38, .c = 39},
{.a = 40, .b = 41, .c = 42},
{.a = 43, .b = 44, .c = 45},
{.a = 46, .b = 47, .c = 48},
},
{
{.a = 49, .b = 50, .c = 51},
{.a = 52, .b = 53, .c = 54},
{.a = 55, .b = 56, .c = 57},
{.a = 58, .b = 59, .c = 60},
},
{
{.a = 61, .b = 62, .c = 63},
{.a = 64, .b = 65, .c = 66},
{.a = 67, .b = 68, .c = 69},
{.a = 70, .b = 71, .c = 72},
},
},
};
printf("----- Before Call By Reference -----\n");
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 3; j++)
{
for (int k = 0; k < 4; k++)
{
printf("x[%d][%d][%d].a = %d ", i, j, k, x[1][i][j].a);
printf("x[%d][%d][%d].b = %d ", i, j, k, x[1][i][j].b);
printf("x[%d][%d][%d].c = %d ", i, j, k, x[1][i][j].c);
printf("\n");
}
printf("\n");
}
printf("\n");
}
fun(&x);
printf("----- After Call By Reference -----\n");
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 3; j++)
{
for (int k = 0; k < 4; k++)
{
printf("x[%d][%d][%d].a = %d ", i, j, k, x[1][i][j].a);
printf("x[%d][%d][%d].b = %d ", i, j, k, x[1][i][j].b);
printf("x[%d][%d][%d].c = %d ", i, j, k, x[1][i][j].c);
printf("\n");
}
printf("\n");
}
printf("\n");
}
return 0;
}
Output is as below
----- Before Call By Reference -----
x[0][0][0].a = 37 x[0][0][0].b = 38 x[0][0][0].c = 39
x[0][0][1].a = 37 x[0][0][1].b = 38 x[0][0][1].c = 39
x[0][0][2].a = 37 x[0][0][2].b = 38 x[0][0][2].c = 39
x[0][0][3].a = 37 x[0][0][3].b = 38 x[0][0][3].c = 39
x[0][1][0].a = 40 x[0][1][0].b = 41 x[0][1][0].c = 42
x[0][1][1].a = 40 x[0][1][1].b = 41 x[0][1][1].c = 42
x[0][1][2].a = 40 x[0][1][2].b = 41 x[0][1][2].c = 42
x[0][1][3].a = 40 x[0][1][3].b = 41 x[0][1][3].c = 42
x[0][2][0].a = 43 x[0][2][0].b = 44 x[0][2][0].c = 45
x[0][2][1].a = 43 x[0][2][1].b = 44 x[0][2][1].c = 45
x[0][2][2].a = 43 x[0][2][2].b = 44 x[0][2][2].c = 45
x[0][2][3].a = 43 x[0][2][3].b = 44 x[0][2][3].c = 45
x[1][0][0].a = 49 x[1][0][0].b = 50 x[1][0][0].c = 51
x[1][0][1].a = 49 x[1][0][1].b = 50 x[1][0][1].c = 51
x[1][0][2].a = 49 x[1][0][2].b = 50 x[1][0][2].c = 51
x[1][0][3].a = 49 x[1][0][3].b = 50 x[1][0][3].c = 51
x[1][1][0].a = 52 x[1][1][0].b = 53 x[1][1][0].c = 54
x[1][1][1].a = 52 x[1][1][1].b = 53 x[1][1][1].c = 54
x[1][1][2].a = 52 x[1][1][2].b = 53 x[1][1][2].c = 54
x[1][1][3].a = 52 x[1][1][3].b = 53 x[1][1][3].c = 54
x[1][2][0].a = 55 x[1][2][0].b = 56 x[1][2][0].c = 57
x[1][2][1].a = 55 x[1][2][1].b = 56 x[1][2][1].c = 57
x[1][2][2].a = 55 x[1][2][2].b = 56 x[1][2][2].c = 57
x[1][2][3].a = 55 x[1][2][3].b = 56 x[1][2][3].c = 57
----- After Call By Reference -----
x[0][0][0].a = 702 x[0][0][0].b = 703 x[0][0][0].c = 704
x[0][0][1].a = 702 x[0][0][1].b = 703 x[0][0][1].c = 704
x[0][0][2].a = 702 x[0][0][2].b = 703 x[0][0][2].c = 704
x[0][0][3].a = 702 x[0][0][3].b = 703 x[0][0][3].c = 704
x[0][1][0].a = 705 x[0][1][0].b = 706 x[0][1][0].c = 707
x[0][1][1].a = 705 x[0][1][1].b = 706 x[0][1][1].c = 707
x[0][1][2].a = 705 x[0][1][2].b = 706 x[0][1][2].c = 707
x[0][1][3].a = 705 x[0][1][3].b = 706 x[0][1][3].c = 707
x[0][2][0].a = 708 x[0][2][0].b = 709 x[0][2][0].c = 710
x[0][2][1].a = 708 x[0][2][1].b = 709 x[0][2][1].c = 710
x[0][2][2].a = 708 x[0][2][2].b = 709 x[0][2][2].c = 710
x[0][2][3].a = 708 x[0][2][3].b = 709 x[0][2][3].c = 710
x[1][0][0].a = 714 x[1][0][0].b = 715 x[1][0][0].c = 716
x[1][0][1].a = 714 x[1][0][1].b = 715 x[1][0][1].c = 716
x[1][0][2].a = 714 x[1][0][2].b = 715 x[1][0][2].c = 716
x[1][0][3].a = 714 x[1][0][3].b = 715 x[1][0][3].c = 716
x[1][1][0].a = 717 x[1][1][0].b = 718 x[1][1][0].c = 719
x[1][1][1].a = 717 x[1][1][1].b = 718 x[1][1][1].c = 719
x[1][1][2].a = 717 x[1][1][2].b = 718 x[1][1][2].c = 719
x[1][1][3].a = 717 x[1][1][3].b = 718 x[1][1][3].c = 719
x[1][2][0].a = 720 x[1][2][0].b = 721 x[1][2][0].c = 722
x[1][2][1].a = 720 x[1][2][1].b = 721 x[1][2][1].c = 722
x[1][2][2].a = 720 x[1][2][2].b = 721 x[1][2][2].c = 722
x[1][2][3].a = 720 x[1][2][3].b = 721 x[1][2][3].c = 722
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