How to remove all non-numeric characters from a variable

Question

How can I remove all text characters (not numbers or float) from a javascript variable ?

function deduct(){
    var getamt= document.getElementById('cf').value; //eg: "Amount is 1000"
    var value1 = 100;
    var getamt2 = (value1-getamt);
    document.getElementById('rf').value=getamt2;
}

I want getamt as number. parseInt is giving NaN result.

possible duplicate of [strip non-numeric characters from string](http://stackoverflow.com/questions/1862130/strip-non-numeric-characters-from-string) -- See second answer `getamt.replace(/[^\d.-]/g, '')` — David Sherret, Feb 20 '15 at 17:11
Note that you need to see one of the non-accepted answers on the dupe to handle floats — James Thorpe, Feb 20 '15 at 17:12

score 5 · Answer 1 · answered Feb 20 '15 at 17:15

You can replace the non-numbers

    var str = "Amount is 1000";
    var num = +str.replace(/[^0-9.]/g,"");
    console.log(num);

or you can match the number

    var str = "Amount is 1000";
    var match = str.match(/([0-9.])+/,"");
    var num = match ? +match[0] : 0;
    console.log(num);

The match could be more specific too

Johny · Accepted Answer · 2018-02-25T08:28:22.613

3

Use regular expression like this:

var getamt= document.getElementById('cf').value; //eg: Amount is 1000
var value1 = 100;
var getamt2 = value1 - getamt.replace( /\D+/g, ''); // this replaces all non-number characters in the string with nothing.
console.log(getamt2);

Try this Fiddle

edited Feb 25 '18 at 08:28

answered Feb 20 '15 at 17:10

Johny

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This only removes the non numeric values from the start of the string, not the middle or end – Humble Rumble Nov 28 '17 at 13:53

How to remove all non-numeric characters from a variable

2 Answers2