Functions

In C, functions specify the types for their arguments and return value.

float add(int x, int y) {
    return (float)(x + y);
}

• The first type, float is the return type.
• add is the name of the function.
• int x, int y are the parameters to the function, and their types are specified.
• x + y adds the two arguments together.
• (float) casts the result to a float.
  • We'll talk more about what cast means later, and the rules for casting to and from certain types.
  • The simple version is that it instructs C to convert the result of x + y to a float value.

Here's how you would call this function:

int main() {
    float result = add(10, 5);
    printf("result: %f\n", result);
    // result: 15.000000
    return 0;
}

It's nice that C functions enforce returning the same type from all return statements, isn't it? In Python, it can be a pain to realize that a function returns different types depending on the path it took.