删除arr数组中的第i个元素的最好做法是?
①
arr.splice(i-1,1)②
arr.slice(0,n).concat(arr.slice(n+1,arr.length));③
Array.prototype.remove = function(dx) { if (isNaN(dx) || dx > this.length) { return false; } for (var i = 0, n = 0; i < this.length; i++) { if (this[i] != this[dx]) { this[n++] = this[i] } } this.length -= 1 }④
for (var i = 0, n = 0; i < this.length; i++) { if (this[i] != this[dx]) { this[n++] = this[i] } }