javascript - 将字符串转换为整数？(Convert a string to an integer?)

Question

如何在JavaScript中将字符串转换为整数？

  ask by translate from so

Answer 1

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

(最简单的方法是使用本机Number函数：)

var x = Number("1000")

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

(如果这对您不起作用，则有parseInt ， 一元plus ， 带有floor的parseFloat和Math.round方法。)

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])

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

(一元加号，如果您的字符串已经是整数形式：)

var x = +"1000";

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

(如果您的字符串是浮点数或可能是浮点数，并且您想要一个整数：)

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

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

(或者，如果您要多次使用Math.floor：)

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

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.

(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。)

Here I use floor.

(在这里我用地板。)

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

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:

(有趣的是，Math.round（例如Math.floor）将进行字符串到数字的转换，因此，如果您想将数字四舍五入（或者如果字符串中有整数），这是一个很好的方法，也许是我的最爱：)

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