从字符串中提取（“获取”）一个数字

本文翻译自：Extract (“get”) a number from a string

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，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,'$2');
alert(thenum);

It still returns #box2 in the alert, how can I get it to work? 它仍会在警报中返回＃box2，我该如何让它工作？

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编号。

---

#1楼

参考：https://stackoom.com/question/fyPj/从字符串中提取-获取-一个数字

---

#2楼

For this specific example, 对于这个具体的例子，

 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. 由于这个答案因某种原因而受到欢迎，这里有一个奖励：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: ' + re + ''; } 

 
Hi, I'm Numex, the Number Extractor Oracle. 
What is your string? 
 
What number do you want to extract? 
 
Insert Coin
 
 

---

#3楼

For a string such as #box2 , this should work: 对于#box2这样的字符串，这应该有效：

var thenum = thestring.replace(/^.*(\d+).*$/i,'$1');

jsFiddle: 的jsfiddle：

• http://jsfiddle.net/dmeku/ http://jsfiddle.net/dmeku/

---

#4楼

Using match function. 使用匹配功能。

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

jsfiddle 的jsfiddle

---

#5楼

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。

---

#6楼

You should try the following: 您应该尝试以下方法：

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

result 结果

1234561613213213