在Javascript中切片数组的每个字符串值元素 [英] Slice each string-valued element of an array in Javascript

问题描述

我有以下数组：

var arr = ["Toyota", "Hyundai", "Honda", "Mazda"];

我想向后切片每个元素，例如：

I want to slice each element backwards, like:

var arr = ["Toyota", "Hyundai", "Honda", "Mazda"].slice(-2);

所以它会返回：

arr = ["Toyo", "Hyund", "Hon", "Maz"];

有可能吗？或者有没有这样做？

Is it possible? or is there anyway of doing this?

推荐答案

你不能使用 slice 直接，因为它与数组有不同的含义，并会返回一个数组元素列表。

You can't use slice directly, as it has a different meaning with an array and will return you a list of array elements.

var arr = ["Toyota", "Hyundai", "Honda", "Mazda"]
arr.slice(0, -2) // returns the elements ["Toyota", "Hyundai"]

为了对每个元素进行切片，你可以使用 .map（）（在IE9 +上）：

In order to do the slice on each element, you can use .map() (on IE9+):

var out = arr.map(function(v) { return v.slice(0, -2) }) 
// or using underscore.js for wider compatibility
var out = _.map(arr, function(v) { return v.slice(0, -2) })
// or using a more modern arrow function
var out = arr.map(v => v.slice(0, -2))

或者，您可以使用循环：

Alternatively, you could just use a loop:

var i, out = []
for (i = 0; i < arr.length; ++i) {
    out.push(arr[i].slice(0, -2))
}

或者，用更现代的语法：

or, in more modern syntax:

const out = new Array(arr.length)
for (let i = 0; i < arr.length; ++i) {
    out[i] = arr[i].slice(0, -2)
}

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