Check if number is an integer in Javascript/jQuery

Question

I've got some JS:

var updateAmount = function (amount, rate) {
    if (rate > 0 && amount.length > 0 && !isNaN(amount) && amount > 0) {
        amount = Math.round(rate * amount * 100) / 100; // multiply rate with amount and then round to 2 decimals
        $('.you-get').show();
        $('#you-get').text(amount + ' ' + $currencyTo.find(':selected').text());
    } else {
        $('.you-get').hide();
    }
};

What I need is a clause that checks if the value generated from amount + $currencyTo.find is a whole number, if it is then add .00 to the end of it.

amount = Number(amount); rate = Number(rate); will this help ? — Triode, Feb 25 '14 at 10:07
Maybe amount.toFixed(2); I'm not sure what you mean by amount + $currencyTo.find as that seams to be a string and not a number since you are appending empty space between + ' ' + — Goran.it, Feb 25 '14 at 10:07

alexP · Answer 1 · 2014-02-25T10:23:30.050

if(amount === parseInt(amount)) //returns `true` if it's a integer


var updateAmount = function (amount, rate) {
    if (rate > 0 && amount.length > 0 && !isNaN(amount) && amount > 0 && amount === parseInt(amount)) { //Edited this line
        if(amount === parseInt(amount)) amount += '.00'; //Added this line
        amount = Math.round(rate * amount * 100) / 100; // multiply rate with amount and then round to 2 decimals
        $('.you-get').show();
        $('#you-get').text(amount + ' ' + $currencyTo.find(':selected').text());
    } else {
        $('.you-get').hide();
    }
};

score 1 · Answer 2 · answered Feb 25 '14 at 10:27

1

There is .toFixed() method.

amount = Math.round(rate * amount * 100) / 100;
amount = amount.toFixed(2);

answered Feb 25 '14 at 10:27

xdazz

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R3tep · Accepted Answer · 2014-02-25T10:47:04.913

0

Try this :

var updateAmount = function (amount, rate) {
  if (rate > 0 && amount.length > 0 && !isNaN(amount) && amount > 0) {
    amount = Math.round(rate * amount * 100) / 100; // multiply rate with amount and then round to 2 decimals
    $('.you-get').show();
    var val = amount + '' + $currencyTo.find(':selected').text();
    if (val === parseInt(val)){// check if val is an Int
      $('#you-get').text(val.toFixed(2));//add .00 if amount + $currencyTo.find is an Int
    }else{  
      $('#you-get').text(val);
    }
  }else{
    $('.you-get').hide();
  }
};

edited Feb 25 '14 at 10:47

answered Feb 25 '14 at 10:12

R3tep

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Hi, thanks, it doesn't seem to add .00 if there's no decimal place in the variable val? – user3087370 Feb 25 '14 at 11:45
[JSfiddle](http://jsfiddle.net/v6rF6/2/) : in this example, `toFixed` adds .00 on an integer. – R3tep Feb 25 '14 at 12:02

score 0 · Answer 4 · edited May 23 '17 at 12:15

0

Can you use the remainder to check if the number is a whole number? E.g.

var val = parseFloat(amount) + parseFloat($currencyTo.find(':selected').text());
if ( val % 1 == 0 ) { /* whole number */ } else {/* not whole number */ }

You could also check that !isNaN(val)

This is essentially the answer suggested from a similar question, see here

edited May 23 '17 at 12:15

Community

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answered Feb 25 '14 at 10:12

Kiran

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Check if number is an integer in Javascript/jQuery

4 Answers4