Logical Operator in C -smartduniya

Introducing to C Logical Opeartors

You use C logical operators to connect expressions and / or variables to form compound conditions. The C logical expression return an integer (int). The result has value 1 if the expression is evaluated to true otherwise it return 0.  C uses the following symbols for the boolean operations AND, OR ,and NOT.

Operator	Meaning
&&	logical AND
||	logical OR
!	logical NOT

 

The AND operator (&&) and OR operator (||) has essential peculiarity:

• The || operator, their operands are evaluated in order from left to right, and if the value of the left operand is sufficient to determine the result of the operation, then the right operand is not evaluated at all.
• The operator && evaluates the right operand only if the left operand yields 1;

The following table illustrates the truth table of the logical operators:

 

a	b	a&&b	a||b	!a
True	True	True	True	False
True	False	False	True	False
False	True	False	True	True
False	False	False	False	True

Example of C Logical Operators

 The following program illustrate the C logical operators:

 

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char** argv) {
int x = 10; int y = 15;

int z = 20;
if (x < y && y < z) {
printf("x > y && y < z\n");
}

if (x > y || y < z) {

printf("x > y || y < z\n");

}

if (!(x > y)) {

printf("!(x > y)\n");

}
return (0);
}

 

Below is the output of the C logical operators demo program:

x > y && y < z
x > y || y < z
!(x > y)