arguments.length-1是什么意思呀？

Question

 arguments.length-1是什么意思呀？

Answer 1

arguments 是 function 的内部变量，他是指这个function接收的所有参数集合，类似数组，并不是真正的数组。比如有一个function test;   你调用的时候 是 test(1,4,8,'asd');  在这个test里 arguments.length === 4; arguments[0] === 1; arguments[1] === 4; arguments[2] === 8; arguments[3] === 'asd' ;  arguments.length 就是指这个function真正接收到的参数个数，也就是你调用时传进去的参数个数。

Answer 2

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