Javascript 从字符串中提取（“获取”）一个数字

Extract ("get") a number from a string

提问by user1022585

I have a string in javascript like `#box2' and I just want the '2' from it.

我在 javascript 中有一个字符串，比如 `#box2'，我只想要它的 '2'。

Tried:

尝试：

var thestring = $(this).attr('href');
var thenum = thestring.replace( /(^.+)(\w\d+\w)(.+$)/i,'');
alert(thenum);

It still returns #box2 in the alert, how can I get it to work?

它仍然在警报中返回 #box2，我怎样才能让它工作？

It needs to accommodate for any length number attached on the end.

它需要适应末端附加的任何长度数字。

回答by georg

For this specific example,

对于这个特定的例子，

 var thenum = thestring.replace( /^\D+/g, ''); // replace all leading non-digits with nothing

in the general case:

在一般情况下：

 thenum = "foo3bar5".match(/\d+/)[0] // "3"

Since this answer gained popularity for some reason, here's a bonus: regex generator.

由于此答案由于某种原因而广受欢迎，因此有一个好处：正则表达式生成器。

function getre(str, num) {
  if(str === num) return 'nice try';
  var res = [/^\D+/g,/\D+$/g,/^\D+|\D+$/g,/\D+/g,/\D.*/g, /.*\D/g,/^\D+|\D.*$/g,/.*\D(?=\d)|\D+$/g];
  for(var i = 0; i < res.length; i++)
    if(str.replace(res[i], '') === num) 
      return 'num = str.replace(/' + res[i].source + '/g, "")';
  return 'no idea';
};
function update() {
  $ = function(x) { return document.getElementById(x) };
  var re = getre($('str').value, $('num').value);
  $('re').innerHTML = 'Numex speaks: <code>' + re + '</code>';
}

<p>Hi, I'm Numex, the Number Extractor Oracle.
<p>What is your string? <input id="str" value="42abc"></p>
<p>What number do you want to extract? <input id="num" value="42"></p>
<p><button onclick="update()">Insert Coin</button></p>
<p id="re"></p>

回答by Jason Marshall

You should try the following:

您应该尝试以下操作：

var txt = "#div-name-1234-characteristic:561613213213";
var numb = txt.match(/\d/g);
numb = numb.join("");
alert (numb);?

result

结果

1234561613213213

回答by Theodoros Klikas

I think this regular expression will serve your purpose:

我认为这个正则表达式将满足您的目的：

var num = txt.replace(/[^0-9]/g,'');

Where txtis your string.

txt你的字符串在哪里。

It basically rips off anything that is not a digit.

它基本上撕掉了任何不是数字的东西。

I think you can achieve the same thing by using this as well :

我认为您也可以通过使用它来实现相同的目的：

var num = txt.replace(/\D/g,'');

回答by xbalaji

Try the following: string.replace(/[^0-9]/g, '');This will delete all non-digit characters, leaving only digits in the string

尝试以下操作：string.replace(/[^0-9]/g, '');这将删除所有非数字字符，只留下字符串中的数字

function retnum(str) { 
    var num = str.replace(/[^0-9]/g, ''); 
    return parseInt(num,10); 
}

console.log('abca12bc45qw'.replace(/[^0-9]/g, ''));
console.log('#box2'.replace(/[^0-9]/g, ''));

回答by Shiplu Mokaddim

Using match function.

使用匹配功能。

var thenum = thestring.match(/\d+$/)[0];
alert(thenum);

jsfiddle

提琴手

回答by Paulo Roberto Rosa

Tried all the combinations cited abovewith this Code and got it working, was the only one that worked on that string -> (12) 3456-7890

使用此代码尝试了上面引用的所有组合并使其正常工作，是唯一可以处理该字符串的组合->(12) 3456-7890

var str="(12) 3456-7890";
str.replace( /\D+/g, '');

Result:"1234567890"

结果："1234567890"

Obs:i know that a string like that will not be on the attr but whatever, the solution is better, because its more complete.

Obs：我知道这样的字符串不会出现在 attr 上，但无论如何，解决方案更好，因为它更完整。

回答by Lacho Tomov

And this is a snippet which extracts prices with currency and formatting:

这是一个使用货币和格式提取价格的片段：

var price = "￡1,739.12";
parseFloat(price.replace( /[^\d\.]*/g, '')); // 1739.12

回答by Eugene Tiurin

you may use great parseInt method

你可以使用很棒的 parseInt 方法

it will convert the leading digits to a number

它将前导数字转换为数字

parseInt("-10px");
// will give you -10

回答by icyrock.com

For a string such as #box2, this should work:

对于诸如 的字符串#box2，这应该有效：

var thenum = thestring.replace(/^.*?(\d+).*/,'');

jsFiddle:

js小提琴：

• http://jsfiddle.net/dmeku/

• http://jsfiddle.net/dmeku/

回答by Robby Shaw

You can use regular expression.

您可以使用正则表达式。

var txt="some text 2";
var numb = txt.match(/\d/g);
alert (numb);

That will alert 2.

这将提醒 2。