Logical Operators in C
There are three logical operators.
1. Logical And(&&)
Logical And operator is represented as double ampersand sign (&&). It is used to combine two relational expressions.
Truth table for Logical AND operator
| Input1 | Input2 | Output |
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
Example
10 >3 && 10>5 = 1
10 >3 && 10<5 = 0
10 <3 && 10<5 = 0
2. Logical OR(||)
Logical OR operator is represented as double pipe sign (||). It is used to combine two relational expressions.
Truth table for Logical OR operator
| Input1 | Input2 | Output |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |
Example
10 >3 || 10>5 = 1
10 >3 || 10<5 = 1
10 <3 || 10<5 = 0
3. Logical NOT(!)
Logical NOT operator is represented as sign of exclamation(!). It is used to reverse the output of a relational expression or logical expression.
Truth table for Logical NOT operator
| Input | Output |
| 0 | 1 |
| 1 | 0 |
Example
!(10 >3 && 10>5) = 0
!(10<5) = 1
!(10 <3 || 10<5) = 1
| Program to demonstrate logical operators. | Output (Line Wise) |
| #include<stdio.h> #include<conio.h> int main() { int a,b,c; |
|
| a=10 | |
| b=3 | |
| printf(”\n%d”, (a>0 && b>0); | 1 |
| printf(”\n%d”, (a<0 && b>0); | 0 |
| printf(”\n%d”, (a>0 || b<0); | 1 |
| printf(”\n%d”, (a<0 && b<0); | 0 |
| printf(”\n%d”, !(a>0); | 0 |
| printf(”\n%d”, !(a<0 && b>0); | 1 |
| getch(); return (0); } |