Implicit return type int in C

Example

Let us look at an example to understand better how the implicit return type works.

Code 1

#include <stdio.h>
fun(int x)
{
    return x*x;
}
int main(void)
{
    printf("%d", fun(5));
    return 0;
}

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Output

25

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In this example, we have used an implicit return type without mentioning the return type.

Code 2

#include<stdio.h>
my_function(int x) {
   return x * 2;
}
main(void) {
   printf("Value is: %d", my_function(50));
}

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Output

Value is: 50

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We have used an implicit return type int without mentioning the return type in this example.

Also Read About, Sum of Digits in C, Tribonacci Series and  Short int in C Programming

Must Read what is storage class in c and Decision Making in C

Frequently Asked Questions

What happens if we do not mention a return type in C?

If we don't provide a return type in C, the compiler uses int as an implicit return type. Even if the return type is int, the C99 standard does not allow it to be removed. This was permitted in the C89 standard. Except for a few style C++ compilers like Turbo C++, the above code is invalid in C++.

How to get rid of the implicit int rule?

The current ISO C standard, issued in 2011, disables the "implicit int" rule and requires an explicit statement for any function called. Compilers don't consistently enforce this by default, but you should be able to and should request more strict warnings.

What is implicit type conversion?

The compiler performs implicit type conversions when the operands are of different data types. The compiler automatically transforms smaller data types into more significant data types. Finally, the expression above evaluates to a 'double' value.

Conclusion

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