如何在JavaScript中将字符串转换为整数？ [英] How to convert a string to an integer in JavaScript?

问题描述

如何在JavaScript中将字符串转换为整数？

How do I convert a string to an integer in JavaScript?

推荐答案

最简单的方法是使用本机 Number 函数：

The simplest way would be to use the native Number function:

var x = Number("1000")

如果这对您不起作用，则有 parseInt ，一元加，带有底数的parseFloat 和 Math.round 方法。

If that doesn't work for you, then there are the parseInt, unary plus, parseFloat with floor, and Math.round methods.

parseInt：

parseInt:

var x = parseInt("1000", 10); // you want to use radix 10
    // so you get a decimal number even with a leading 0 and an old browser ([IE8, Firefox 20, Chrome 22 and older][1])

一元加
（如果您的字符串已经是整数形式）

unary plus if your string is already in the form of an integer:

var x = +"1000";

如果您的字符串是或可能是浮点型，并且您想要一个整数：

if your string is or might be a float and you want an integer:

var x = Math.floor("1000.01"); //floor automatically converts string to number

，或者，如果要使用Math.floor几次：

or, if you're going to be using Math.floor several times:

var floor = Math.floor;
var x = floor("1000.01");

如果您是在调用parseInt时忘记将基数放入的类型，则可以使用parseFloat并根据需要将其四舍五入。

If you're the type who forgets to put the radix in when you call parseInt, you can use parseFloat and round it however you like. Here I use floor.

var floor = Math.floor;
var x = floor(parseFloat("1000.01"));

有趣的是，Math.round（如Math.floor）将进行字符串到数字的转换，所以如果您想将数字四舍五入（或者如果字符串中有整数），这是一种很好的方法，也许是我的最爱：

Interestingly, Math.round (like Math.floor) will do a string to number conversion, so if you want the number rounded (or if you have an integer in the string), this is a great way, maybe my favorite:

var round = Math.round;
var x = round("1000"); //equivalent to round("1000",0)

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