Is assigned expression always evaluated even if not needed?

[yukulele]

in this example:

let a = 0;
let b = true;
b = b || a++;
console.log(a); // 0

a++ is not evaluated.

in this case:

let a = 0;
let b = true;
b ||= a++;
console.log(a); // ?

should a++ be executed?

[ljharb]

No, see #3 (comment)

[jridgewell]

No, a will be 0.

[jridgewell]

See https://babeljs.io/repl#?browsers=defaults%2C%20not%20ie%2011%2C%20not%20ie_mob%2011&build=&builtIns=false&spec=false&loose=false&code_lz=DYUwLgBAhhC8EAYDcAoUkBGcJgE4FcRUsAfE-KAaktSlFzAAooBKJIA&debug=false&forceAllTransforms=false&shippedProposals=false&circleciRepo=&evaluate=true&fileSize=false&timeTravel=false&sourceType=module&lineWrap=true&presets=stage-2&prettier=false&targets=&version=7.9.6&externalPlugins=