Upward communication

Upward communication

In upward communication, the called function sends data back to the called function without receiving any data from it. A good example of this type of communication is, when the called function reads the data from the keyboard, the data needs to be passed back to the called function.

int main(void)

{

int a;

int b;

..

upFun(&a, &b);

...

} //main

void upFun(int*ax, int*ay)

{

*ax=23;

*ay=8;

return;

} //upFun

To send data from the called function to the calling function:

-we need to use a symbol ‘&’ (address) in front of the data variable when we call the function.

-we need to use the * symbol after the data type when we declare the address variable.

-we need to use the * in front of the variable when we store data indirectly.

//Function Declaration

void upfun(int *ax, int*ay)

int main(void)

{

// Local Declarations

int a;

int b;

//Statements

upFun(&a, &b);

printf(“%d\n”,a,b);

return 0;

} //main

void upFun(int *ax, int *ay)

{

//Statement

*ax=23;

*ay=8;

return;

} //upFun

Bidirectional communication:

In upward communication, the called function sends data back to the called function without receiving any data from it. A good example of this type of communication is, when the called function reads the data from the keyword, the data needs to be passed back to the called function.

int main(void)

{

int a;

int b;

...

biFun(&a, &b);

...

} //main

void biFun(int* ax, int* ay)

{

*ax = *ax+2;

*ay = *ay/*ax;

return;

} //biFun

//Function Declaration

void biFun (int* ax, int* ay);

int main(void)

{

int a=2;

int b=6;

//Statements

...

biFun (&a, &b)

...

return 0;

} //main

void bifun(int* ax, int* ay);

{

*ax = *ax+2;

*ay = *ay/*ax;

return;

} //biFun