Strict mode - JavaScript | MDN

Note: Sometimes you'll see the default, non-strict mode referred to as sloppy mode. This isn't an official term, but be aware of it, just in case. JavaScript's strict mode is a way to opt in to a restricted variant of JavaScript, thereby implicitly opting-out of "sloppy mode". Strict mode isn't just a subset: it intentionally has different semantics from normal code. Strict mode code and non-stric

[juner]

@YumiSora 厳格モードでは、関数宣言をステートメント内またはブロック内で入れ子にすることはできません。関数宣言は、関数本体内の最上位のレベルまたは直接でのみ記述できます。 QT: 厳格モード (JavaScript)

[turusuke_0]

厳格モード(use strict)の説明