在coffeescript中这很简单:
coffee> a = ['a', 'b', 'program']
[ 'a', 'b', 'program' ]
coffee> [_..., b] = a
[ 'a', 'b', 'program' ]
coffee> b
'program'
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es6是否允许类似的东西?
> const [, b] = [1, 2, 3]
'use strict'
> b // it got the second element, not the last one!
2
> const [...butLast, last] = [1, 2, 3]
SyntaxError: repl: Unexpected token (1:17)
> 1 | const [...butLast, last] = [1, 2, 3]
| ^
at Parser.pp.raise (C:\Users\user\AppData\Roaming\npm\node_modules\babel\node_modules\babel-core\node_modules\babylon\lib\parser\location.js:24:13)
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当然我可以用es5方式做到 -
const …Run Code Online (Sandbox Code Playgroud)