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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