JavaScript Logical_assignment Guide
Logical assignment operators combine logical operators with assignment: &&=, ||=, ??=. The guide walks through Logical Assignments. `x ||= y` — assign if x is falsy. `x &&= y` — assign if x is truthy. `x ??= y` — assign if x is null/undefined. Examples: `obj.prop ??= []` — init array if missing. `element.innerHTML &&= ""` — clear only if set. `config.timeout ||= 3000` — default if not set (including 0). The guide is organized into 1 sections that build on each other, each pairing a prose explanation with runnable code. Related guides: Arrays, Strings, Numbers, Math, Date. This is one of 145 JavaScript guides on JS Reference — see the full list on the guides page. Practice what you learn in the JavaScript playground, and look up any unfamiliar term in the JavaScript glossary.