TypeScript Logical Operators

TypeScript logical operators are similar to what we have learned in JavaScript logical operators. These operators help in comparing boolean expressions and producing a single boolean value as result. 1. Logical Operators Operator Description Logical AND operator – && If both operands (or expressions) are true, then result …

TypeScript logical operators are similar to what we have learned in JavaScript logical operators. These operators help in comparing boolean expressions and producing a single boolean value as result.

1. Logical Operators

Operator Description

Logical AND operator – &&

If both operands (or expressions) are true, then result will be true, else false.

let firstVar = true;
let secondVar = false;
 
console.log( firstVar && secondVar ); //false
console.log( firstVar && true );    //true
console.log( firstVar && 10 );      //10 which is also 'true'
console.log( firstVar && '10' );    //'10'  which is also 'true'

Read More: Truthy and Falsy

Logical OR operator – ||

If any of the two operands (or expressions) are true, then result will be true, else false.

let firstVar = true;
let secondVar = false;
 
console.log( firstVar || secondVar ); //true
console.log( firstVar || true );    //true
console.log( firstVar || 10 );      //true
console.log( firstVar || '10' );    //true

Logical NOT operator – !

It is used to reverse the logical state of its operand. It converts true to false, and vice-versa.

let firstVar = 10;
let secondVar = 20;
 
console.log( !true );   //false
console.log( !false );    //true
console.log( !firstVar ); //false
console.log( !null );   //true

Happy Learning !!

TypeScript Logical Operators

1. Logical Operators

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