Logical Operators

Logical operators enable you to evaluate the truth of multiple expressions, establishing intricate and accurate conditions for your program.

Imagine you need to plot a point on a Cartesian coordinate system. You can only plot this point when you have both the x-coordinate and the y-coordinate. If even one of these coordinates is absent, the point can't be plotted.

We'll focus on three primary logical operators:

Symbol	Name	Usage Example	Description
`&&`	AND	`a && b`	a AND b
`\|\|`	OR	`a \|\| b`	a OR b
`!`	NOT	`!a`	NOT a

These operators return either true or false, depending on the given conditions.

With the introduction of the C99 standard, working with boolean data has become more straightforward thanks to the bool (or _Bool) data type. This data type can only hold two values: 1 (true) or 0 (false).

Main


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#include <stdio.h>

int main()
{
	int x = 45;
	int y = -4;

	/* Using AND operator: 
	if `x` and `y` equals `true` (exists)), 
	point will equal `1` */
	bool point = (x && y); // x = true AND y = true

	printf("Point exists, because x and y exists\n");
	printf("Result of expression equal: %d\n", point);

	return 0;
}

To provide more context:

Main


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#include <stdio.h>

int main()
{
	int x = 45;
	int y = 150;

	bool point = (x < 50 && y > 100); // (x < 50) AND (y > 100)

	printf("Is the expression logically correct?\n");
	printf("%d\n", point);

	return 0;
}

Logical operators really shine when used in conjunction with conditional statements and loops.

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Section 3. Chapter 6