javascript / intermediate
Snippet
Logical Assignment Operators
Logical assignment operators combine logical operations (??, ||, &&) with assignment (=). They are useful for setting default values or updating state conditionally.
snippet.js
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let user = {id: 101,preferences: { theme: 'dark' },accessCount: 0};// Nullish coalescing assignment (assigns if null or undefined)user.preferences.lang ??= 'en';// Logical OR assignment (assigns if falsy)user.accessCount ||= 1;// Logical AND assignment (assigns if truthy)user.id &&= 'ID_' + user.id;console.log(user);
Breakdown
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user.preferences.lang ??= 'en';
Assigns 'en' only if lang is null or undefined (not for empty string or 0).
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user.accessCount ||= 1;
Assigns 1 because the current value (0) is falsy.