在JavaScript语法Jn传播后加上分号会中断执行，并显示错误"Unexpected token =". [英] Having semicolon after spread syntax jn javascript breaks execution with error "Unexpected token ="

问题描述

有人可以告诉我为什么吗

Can someone explain me why

const getabc = ()=> ({a:'aa',b:'bb',c:123});
let a, b, c;
{ a, b, c } = {...getabc()}

这有效

和

const getabc = ()=> ({a:'aa',b:'bb',c:123});
let a, b, c;
{ a, b, c } = {...getabc()};

这不是(请注意分号结尾)

this does not (note semicolon at the end)

推荐答案

这与扩展语法或分号无关.

This has nothing to do with spread syntax or semicolons.

没有像var，const或let之类的对象进行对象分解的分配必须使用括号(或以其他方式在包含它的较大语句中以表达式的形式出现)，因为否则JS将将开头括号解析为一个块的开头:

Object destructuring assignments that are not preceded with something like var, const, or let must use parentheses (or in some other way occur as a an expression within a larger statement containing it) because otherwise JS will parse the opening brace as the beginning of a block:

const getabc = ()=>({a:'aa',b:'bb',c:123});
let a, b, c;
({ a, b, c } = {...getabc()});

同时，这里没有使用扩展语法的意义，因此您可以删除它:

At the same time, there is no point in using spread syntax here, so you can remove that:

const getabc = ()=>({a:'aa',b:'bb',c:123});
let a, b, c;
({ a, b, c } = getabc());

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