How do I use JavaScript for number formatting?

Question

I want to use JavaScript to restrict input on a text box to currency number formatting. For example:

<input type="text" value="2,500.00" name="rate" />

As given above, the text box should accept only numbers, commas and a period.

But, after the period it should accept two digits after numbers.

How do I accomplish this? Please clarify.

• Gnaniyar Zubair

Answer 1

parseFloat can convert a string to a float and toFixed can set how many decimal places to keep.

function numToCurrency(num){
    return parseFloat(num).toFixed(2);
}


numToCurrency("4.2334546") // returns 4.23