Removing everything except numbers in a string

Question

I\'ve made a small calculator in javascript where users enter the interest rate and amount the they want to borrow, and it calculates how much of an incentive they might get

Answer 1

This is the shortest:

replace(/\D/g,'');

Answer 2

there is very good plugin you can use it. For example

//include jQuery.js and autoNumeric-1.8.3.js javascript files in the header.

    <script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"> </script>
    <script src="autoNumeric-1.8.0.js" type=text/javascript> </script>

  // this example uses the id selector & no options passed    
  jQuery(function($) {
      $('#someID_defaults').autoNumeric('init');    
  });

see check below http://www.decorplanit.com/plugin/

Answer 3

try this

Eg:

var a="4.52%"
var stringLength = a.length;
var lastChar = a.charAt(stringLength - 1); 

if(lastChar.match(/[^\w\s]/)) {
    a=a.substring(0,stringLength - 1);
}

alert(a);

Now you can typecast to number

Answer 4

Here is my solution:

const filterNum = (str) => {
  const numericalChar = new Set([ ".",",","0","1","2","3","4","5","6","7","8","9" ]);
  str = str.split("").filter(char => numericalChar.has(char)).join("");
  return str;
}

console.log(filterNum("143.33$"));
// 143.33

Answer 5

You should probably test for and reject invalid values but if you have to clean a dodgy string into a number then this should work:

var inStr = "a12ab.c34...h.re567";
var justOneDot = inStr.replace(/[.](?=.*?\.)/g, '');//look-ahead to replace all but last dot
var outStr = parseFloat(justOneDot.replace(/[^0-9.]/g,'')).toFixed(2); //parse as float and round to 2dp 
// = 1234.57

Play with it in this JS Bin.

Answer 6

Note that you should use the correct DOM id to refer via getElementById. You can use the .replace() method for that:

var loan_amt = document.getElementById('loan_amt');
loan_amt.value = loan_amt.value.replace(/[^0-9]/g, '');

But that will remove float point delimiter too. This is an answer to your question, but not a solution for your problem. To parse the user input as a number, you can use parseFloat() - I think that it will be more appropriate.