我尝试编写自己的Array.prototype.join（）有什么问题？

Question

I have been trying to implement a bunch of higher order functions myself. Just for the fun of it.

Today though, I found myself stuck on the attempt to reproduce the Array.join method.

I have set myself a challenge not to use any loops such as for or while , use as little if statements as possible and reduce the number of variables used.

Below is my attempt:

 Array.prototype.implode = function(glue) { return (function loop(arr, str) { return (arr.length > 1 ? loop(arr.slice(0, 1), str + arr[0] + (glue || '')) : str); })(this, ''); }; const arr = ['a', 'b', 'c', 'd', 'e', 'f']; console.log(arr.implode('#')); // a# 

Answer 1

You should start handling the end case of a recursive function, than the other. It's easier :)

However, you should slice from the second element to the end, not only the first element.

 Array.prototype.implode = function (glue) { return (function loop(array, glue) { return ( array.length === 1 ? array[0] : array[0] + glue + loop(array.slice(1), glue) ) })(this, glue || '') } const arr = ['a', 'b', 'c', 'd', 'e', 'f']; console.log(arr.implode('#')); // a#b#c#d#e#f