If a function has to return a value to the calling function, it is done through the return statement. It may be possible that a function does not return any value; only the control is transferred to the calling function.
The syntax for the return statement is:
return (expression);
We have seen in the square( ) function, the return statement, which returns an integer value.
Points to remember:
- You can pass any number of arguments to a function but can return only one value at a time.
For example, the following are the valid return statements
(a) return (5);
(b) return (x*y);
For example, the following are the invalid return statements
(c) return (2, 3);
(d) return (x, y);
- If a function does not return anything, void specifier is used in the function declaration.
For example:
void square (int no)
{
int sq;
sq = no*no;
printf (“square is %d”, sq);
}
• All the function’s return type is by default is “int”, i.e. a function returns an integer value if no type specifier is used in the function declaration.
Some examples are:
(i) square (int no); /* will return an integer value */
(ii) int square (int no); /* will return an integer value */
(iii) void square (int no); /* will not return anything */
• What happens if a function has to return some value other than integer? The answer is very simple: use the particular type specifier in the function declaration.
For example, consider the code fragments of function definitions below:
1) Code Fragment - 1
char func_char( …….. )
{
…………….
…………….
……………
}
2) Code Fragment - 2
float func_float (……..)
{
float f;
…………..
…………..
…………..
return(f);
}
Thus from the above examples, we see that you can return all the data types from a function, the only condition being that the value returned using return statement and the type specifier used in function declaration should match.
• A function can have many return statements. This thing happens when some condition based returns are required.
For example,
/*Function to find greater of two numbers*/
int greater (int x, int y)
{
if (x>y)
return (x);
else
return (y);
}
• And finally, with the execution of the return statement, the control is transferred to the calling function with the value associated with it.
In the above example if we take x = 5 and y = 3, then the control will be transferred to the calling function when the first return statement will be encountered, as the condition (x > y) will be satisfied. All the remaining executable statements in the function will not be executed after this returning.