Concept of function in C?

Jan 12 • Resources • 2314 Views • 6 Comments on Concept of function in C?

quest1 Define function?

A function is a module or block of program code which deals with a particular task. Making functions is a way

of isolating one block of code from other independent blocks of code.

quest 2Methods of passing in functions?

There are two ways to pass parameters to a function:

• Pass by Value: mechanism is used when you don’t want to change the value of passedparamters. When parameters are passed by value then functions in C create copies of the passed in variables

  and do required processing on these copied variables.

• Pass by Reference mechanism is used when you want a function to do the changes in passedparameters and reflect those changes back to the calling function. In this case only addresses of the

  variables are passed to a function so that function can work directly over the addresses.

quest 3 Example of pass by value?

#include <stdio.h>
void swap( int p1, int p2 );

int main()
{
   int a = 10;
   int b = 20;

   printf("Before: Value of a = %d and value of b = %dn", a, b );
   swap( a, b );
   printf("After: Value of a = %d and value of b = %dn", a, b );
}

void swap( int p1, int p2 )
{
    int t;

    t = p2;
    p2 = p1;
    p1 = t;
   printf("Value of a (p1) = %d and value of b(p2) = %dn", p1, p2 );
}

quest 4 Example of pass by reference?

#include <stdio.h>

void swap( int p1, int p2 );

int main()
{
   int a = 10;
   int b = 20;

   printf("Before: Value of a = %d and value of b = %dn", a, b );
   swap( a, b );
   printf("After: Value of a = %d and value of b = %dn", a, b );
}

void swap( int p1, int p2 )
{
    int t;

    t = p2;
    p2 = p1;
    p1 = t;
   printf("Value of a (p1) = %d and value of b(p2) = %dn", p1, p2 );
}

quest 5 concept of return in functions?

A return keyword is used to return a value and datatype of the returned value is specified before the

name of function. In this case function returns total which is int type. If a function does not

return a value then void keyword can be used as return value.

quest 6 what is function defination?

When a function is defined at any place in the program then it is called function definition. At the time of  definition of a function actual logic is implemented with-in the function.

quest 7 Some features of function in c?

1) Reusability of Code : Means Once a Code has Developed then we can use that Code

any Time.

2) Remove Redundancy: Means a user doesn’t need to Write Code Again and Again.

3) Decrease Complexity: Means a Large program will be Stored in the Two or More

Functions. So that this will makes easy for a user to understand that Code.

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