return Can Return an Expression

There are several ways how you could write the is_between function on the previous page. First of all, you could've avoided using any boolean operators at all:

int is_between(int x, int a, int b) {
	if (x < a) {
		return 0;  /* remember: return exits the function */
	}
	if (x > b) {
		return 0;
	}
	return 1;
}

You could've combined that into one expression with || or with && – the following implementations do the same thing:

int is_between(int x, int a, int b) {
	if (x < a || x > b) {
		return 0;
	}
	return 1;
}

int is_between(int x, int a, int b) {
	if (x >= a && x <= b) {
		return 1;
	}
	return 0;
}

But one thing I haven't explicitly mentioned above is that you can avoid using if by writing a single return statement:

int is_between(int x, int a, int b) {
	return (x >= a && x <= b);
}

The way it works is: as you remember, each comparison operator results in 0 or 1, and the && will evaluate to 1 (a true value) if it sees a true value on both sides.

Depending on a situation, it might be easier to squeeze the function logic into a single return statement, or have multiple conditions with individual return statements.