Logical OR Operator

Dart Logical OR Operator takes two boolean values as operands and returns the result of their logical OR gate operation.

Logical OR Operator returns true if any of the operands is true. Therefore, we use OR Operator to check if any of the given conditions (operands) is true.

Symbol

|| symbol is used for Logical OR Operator.

Syntax

The syntax for Logical OR Operator is

operand_1 || operand_2

where operand_1 and operand_2 are boolean values or expressions that evaluate to boolean values.

Truth Table

The truth table of OR operation is shown in the following.

operand_1operand_2operand_1 || operand_2
truetruetrue
truefalsetrue
falsetruetrue
falsefalsefalse

Examples

Check if given number is even or divisible by 5

In the following example, we check if the given integer number n is even, or divisible by 5, or both. Here there are two conditions. First condition is that if the given number is even n % 2 == 0, and the second condition is that if the number is divisible by 5, n % 5 == 0. The number must satisfy at least one of these two conditions, and, therefore we will use Logical OR operator to join these two conditions (n % 2 == 0) || (n % 5 == 0).

main.dart

import 'dart:io';

void main(){
    print('Enter n');
    var n = int.parse(stdin.readLineSync()!);

    if ( (n % 2 == 0) || (n % 5 == 0) ) {
        print('$n is either even or divisible by 5, or both.');
    } else {
        print('$n is neither even, nor divisible by 5.');
    }
}

Output

Enter n
12
12 is either even or divisible by 5, or both.

Output

Enter n
25
25 is either even or divisible by 5, or both.

Output

Enter n
13
13 is neither even, nor divisible by 5.

Conclusion

In this Dart Tutorial, we learned about Logical OR Operator, its syntax and usage, with examples.