我如何在javascript中的标量乘以一个阵列中的每个成员？ [英] How do I multiply each member of an array by a scalar in javascript?

问题描述

例如，我该如何实现下面的不反复阵列上

  VAR一个= [1，2，3] * 5; //一个应等于[5，10，15]
 

解决方案

<一个href=\"https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/map\"><$c$c>Array.map()提供给用户的IE浏览器IE9作为的，所以如果你根本不关心的兼容性，可以使用这样的：

  VAR一个= [1，2，3] .MAP（函数（X）{返回X * 5;}）;
 

对于JavaScript 1.8，这是短，你可以去：

  VAR一个= [1，2，3] .MAP（函数（x）x * 5）;
 

如果您需要最大的浏览器兼容性，你必须忍受一个循环。

无论哪种方式，你会遍历数组结束; Array.map（）只是使它不那么明显你这样做。

For example, how do I achieve the following without iterating over the array?

var a = [1, 2, 3] * 5;  // a should equal [5, 10, 15]

解决方案

Array.map() is available to IE users as of IE9, so if you don't care about compatibility at all you can use this:

var a = [1, 2, 3].map(function(x) { return x * 5; });

For JavaScript 1.8, this is as short as you can go:

var a = [1, 2, 3].map(function(x) x * 5);

If you need maximal browser compatibility, you'll have to put up with a loop.

Either way you'll be iterating over the array; Array.map() just makes it less obvious you're doing so.

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