'How can I extract a number from a string in JavaScript?

I have a string in JavaScript (e.g #box2) and I just want the 2 from it.

I tried:

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?

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

Solution 1:^[1]

For this specific example,

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

in the general case:

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

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

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>

Solution 2:^[2]

You should try the following:

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

result

1234561613213213

Solution 3:^[3]

I think this regular expression will serve your purpose:

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

Where txt is your string.

It basically rips off anything that is not a digit.

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

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

Solution 4:^[4]

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

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, ''));

Solution 5:^[5]

Using match function.

var thenum = "0a1bbb2".match(/\d+$/)[0];
console.log(thenum);

Solution 6:^[6]

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

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

Solution 7:^[7]

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

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

Result: "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.

Solution 8:^[8]

you may use great parseInt method

it will convert the leading digits to a number

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

Solution 9:^[9]

You can extract numbers from a string using a regex expression:

let string = "xxfdx25y93.34xxd73";
let res = string.replace(/\D/g, "");
console.log(res);

output: 25933473

Wrap it into vanilla javascript function:

function onlyNumbers(text){
    return text.replace(/\D/g, "");
}

Solution 10:^[10]

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

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

jsFiddle:

http://jsfiddle.net/dmeku/

Solution 11:^[11]

function justNumbers(string) 
{
   var numsStr = string.replace(/[^0-9]/g,'');
   return parseInt(numsStr);
}
    
console.log(justNumbers('abcdefg12hijklmnop'));

You can do a function like this

function justNumbers(string) 
    {
        var numsStr = string.replace(/[^0-9]/g,'');
        return parseInt(numsStr);
    }

remember: if the number has a zero in front of it, the int wont have it

Solution 12:^[12]

If you want to parse a number from a price like $6,694.20.
It can be done this way:

parseFloat('$6,694.20'.replace( /^\D|,+/g, ''))

or via function:

function parsePrice(value) {
  return parseFloat(value.replace( /^\D|,+/g, ''))
}
parsePrice('$6,694.20') // 6694.2

Solution 13:^[13]

You can use regular expression.

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

That will alert 2.

Solution 14:^[14]

If someone need to preserve dots in extracted numbers:

var some = '65,87 EUR';
var number = some.replace(",",".").replace(/[^0-9&.]/g,'');
console.log(number); // returns 65.87

Solution 15:^[15]

You can use Underscore String Library as following

var common="#box"
var href="#box1"

_(href).strRight(common)

result will be : 1

See :https://github.com/epeli/underscore.string

DEMO:
http://jsfiddle.net/abdennour/Vyqtt/
HTML Code :

<p>
    <a href="#box1" >img1</a>
    <a href="#box2" >img2</a>
    <a href="#box3" >img3</a>
    <a href="#box4" >img4</a>
</p>
<div style="font-size:30px"></div>

JS Code :

var comm="#box"
$('a').click(function(){
  $('div').html(_($(this).attr('href')).strRight(comm))})

if you have suffix as following :

href="box1az"

You can use the next demo :

http://jsfiddle.net/abdennour/Vyqtt/1/

function retrieveNumber(all,prefix,suffix){
 var left=_(all).strRight(prefix);
 return _(left).strLeft(suffix);

}

Solution 16:^[16]

With Regular Expressions, how to get numbers from a String, for example:

String myString = "my 2 first gifts were made by my 4 brothers";
myString = myString .replaceAll("\\D+","");
System.out.println("myString : " + myString);

the result of myString is "24"

you can see an example of this running code here: http://ideone.com/iOCf5G

Solution 17:^[17]

Here's a solt. that checks for no data

var someStr = 'abc'; // add 123 to string to see inverse

var thenum = someStr.match(/\d+/);

if (thenum != null )
{
    console.log(thenum[0]);
}
else
{
 console.log('no number');
}

Solution 18:^[18]

Use this one-line code to get the first number in a string without getting errors:

var myInt = parseInt(myString.replace(/^[^0-9]+/, ''), 10);

Solution 19:^[19]

please check below javaScripts, there you can get only number

var txt = "abc1234char5678#!9";
var str = txt.match(/\d+/g, "")+'';
var s = str.split(',').join('');
alert(Number(s));

output : 1234567789

Solution 20:^[20]

var elValue     = "-12,erer3  4,-990.234sdsd";

var isNegetive = false;
if(elValue.indexOf("-")==0) isNegetive=true;

elValue     = elValue.replace( /[^\d\.]*/g, '');
elValue     = isNaN(Number(elValue)) ? 0 : Number(elValue);

if(isNegetive) elValue = 0 - elValue;

alert(elValue); //-1234990.234

Solution 21:^[21]

let str = "Total Work Duration: 189.56 Hrs.Present: 23.5 Absent: 2";
let numArr = str.match(/[\d\.]+/g)
numArr = numArr.filter(n => n != '.')
console.log(numArr)

Solution 22:^[22]

This answer will cover most of the scenario. I can across this situation when user try to copy paste the phone number

  $('#help_number').keyup(function(){
    $(this).val().match(/\d+/g).join("")
  });

Explanation:

str= "34%^gd 5-67 6-6ds"

str.match(/\d+/g)

It will give a array of string as output >> ["34", "56766"]

str.match(/\d+/g).join("")

join will convert and concatenate that array data into single string

output >> "3456766"

In my example I need the output as 209-356-6788 so I used replace

  $('#help_number').keyup(function(){
    $(this).val($(this).val().match(/\d+/g).join("").replace(/(\d{3})\-?(\d{3})\-?(\d{4})/,'$1-$2-$3'))
  });

Solution 23:^[23]

You need to add "(/\d+/g)" which will remove all non-number text, but it will still be a string at this point. If you create a variable and "parseInt" through the match, you can set the new variables to the array values. Here is an example of how I got it to work:

    var color = $( this ).css( "background-color" );
    var r = parseInt(color.match(/\d+/g)[0]);
    var g = parseInt(color.match(/\d+/g)[1]);
    var b = parseInt(color.match(/\d+/g)[2]);

Solution 24:^[24]

To return a int from the string you can do following code. It removes all not number characters and return integer.

Number("strin[g]3".replace(/\D+/g, ""))

Solution 25:^[25]

changeStrangeDate(dateString: string) {
var sum = 0;
var numbers = dateString.match(/\d+/g);
if (numbers.length > 1) {
  numbers.forEach(element => {
    sum += parseInt(element);
  }
  );
}
console.log(new Date(sum).toDateString());
return new Date(sum).toUTCString();

}

You can do it like that and then call function where you need, with parameter.

this.changeStrangeDate('/Date(1551401820000-0100)/');

Solution 26:^[26]

In one of my projects I had to take a rating value from a string this is what I used :

 let text = '#xbox2'
  let num = text.trim().
  split('').
  map(num => Number(num)).
  filter(x => Number.isInteger(x)

)

Solution 27:^[27]

written without regex

// Without Regex 

function extractNumber(string) {
  let numArray = string.split('').map(item => {
    if (typeof +item === 'number' && !isNaN(+item)) return +item
  })
  return +numArray.join('')
}

extractNumber('@1200milion$')  // 1200

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1
Solution 2	asgoth
Solution 3	Fran Verona
Solution 4
Solution 5	vsync
Solution 6	LachoTomov
Solution 7	Paulo Roberto Rosa
Solution 8	Eugene Tiurin
Solution 9
Solution 10	Wiktor StribiÅ¼ew
Solution 11	Koga
Solution 12	Code4Art
Solution 13	Robby Shaw
Solution 14	BaronBaleron
Solution 15
Solution 16
Solution 17	Gene Bo
Solution 18	Ruslan
Solution 19	Thilina Sampath
Solution 20	Manoj Chavanke
Solution 21	Stone
Solution 22	Vinay Kumar
Solution 23	chineseducks
Solution 24	dawid debinski
Solution 25	Irakli Kardava
Solution 26	O'talb
Solution 27	ehsan parsania

'How can I extract a number from a string in JavaScript?

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