Logical Operators

Logical assignment operators combines the logical operations(&&, || or ??) with assignment. They are quite useful for assigning default values to variables.

&&=:

The &&= operator performs the assignment only when the left operand is truthy.

let x = 10;
let y = 20;
x &&= y;
console.log(x); // 20

The above logical assignment operation can be expanded to:

x = x && (x = y);
(OR)
if (x) {
x = y;
}

||=:

The ||= operator performs the assignment only when the left operand is falsy.

let x = 0;
let y = 20;
x ||= y;
console.log(x); // 20

The above logical assignment operation can be expanded to:

x = x || (x = y);
(OR)
if (!x) {
x = y;
}

??=:

The ??= operator performs the assignment only when the left operand is null or undefined.

let x;
let y = 1;
x ??= y;
console.log(x); // 1

The above logical assignment operation can be expanded to:

x ?? (x = y);
(OR)
if (!x) {
x = y;
}

ES2022 Or ES13

ECMAScript 2022 or ES13 has been released in the month of June 2022 with some of important features in JavaScript.