Develop Reference

Adding Two Decimal Places using JavaScript

Good day Everyone!
I want to know how to return the output with two decimal places. Instead of 10,000 I want it to return 10,000.00. Also I already put .toFixed(2) but it's not working.
When the amount has decimal number other than zero, the values appear on the printout, but when the decimal number has a zero value, the Zeros won't appear on the printout.
Also, I have added a value of Wtax that was pulled-out on a "Bill Credit" Transaction.
Output:

Numeral.js - is a library that you can use for number formatting.
With that you can format your number as follows:
numeral(10000).format('$0,0.00');
Hope this will help you.

You can try this
var x = 1000; // Raw input
x.toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,') //returns you 1,000.00
Alternately you can use Netsuite's currency function too
nlapiFormatCurrency('1000'); // returns you 1,000.00
nlapiFormatCurrency('1000.98'); // returns you 1,000.98

You might consider below code. It can round off decimal values based on the decimal places.
This also addresses the issue when rounding off negative values by getting first the absolute value before rounding it off. Without doing that, you will have the following results which the 2nd sample is incorrect.
function roundDecimal(decimalNumber, decimalPlace)
{
//this is to make sure the rounding off is correct even if the decimal is equal to -0.995
var bIsNegative = false;
if (decimalNumber < 0)
{
decimalNumber = Math.abs(decimalNumber);
bIsNegative = true;
}
var fReturn = 0.00;
(decimalPlace == null || decimalPlace == '') ? 0 : decimalPlace;
var multiplierDivisor = Math.pow(10, decimalPlace);
fReturn = Math.round((parseFloat(decimalNumber) * multiplierDivisor).toFixed(decimalPlace)) / multiplierDivisor;
fReturn = (bIsNegative) ? (fReturn * -1) : fReturn;
fReturn = fReturn.toFixed(decimalPlace)
return fReturn;
}
Below are the test sample
And this test sample after addressing the issue for negative values.

Save integer as float

function prec(numb){
var numb_string = numb.toString().split('.')
return numb_string[(numb_string.length - 1)].length
}
function randy(minimum, maximum) {
var most_accurate = Math.max ( prec(minimum), prec(maximum) );
return ( ( Math.random() * ( maximum - minimum ) + minimum ).toFixed( most_accurate ) );
}
// returns random numbers between these points. 1 decimal place of precision:
console.log( randy(2.4,4.4) );
// returns random numbers between these points. 3 decimal places of precision:
console.log( randy(2.443,4.445) );
// returns random numbers between these points. Want 3 decimal places of precision. However, get 0:
console.log( randy(2.000,4.000) );
// Why do I get 0 decimal places? Because floats are rounded into integers automatically:
console.log( 4.0 ); // want 4.0 to be logged. Instead I get '4'
You don't need to read how the functions work. Just the console logs.
Basically, I need to return a random number between two points to a degree of precision. The precision is automatically derived from the most precise float passed to the randy function.
This works fine when the number range is 3.5 3.7 or 34.4322 800.3233 but not 2.0, 3.0 or 4.0000, 5.0000
Then the number is appears to be automatically saved as an integer:
console.log( 2.0 ) //=> 2
I want to extend the Number prototype so that 2.0 is saved as 2.0 so that this function can find the precision:
function prec(numb){
var numb_string = numb.toString().split('.')
return numb_string[(numb_string.length - 1)].length
}
It currently thinks that 3.000000000 has a precision of 0 decimal places because if 3E8 is passed in as the numb parameter, it's read as 3. I want it read as 3.000000000
While I can do this randy(2.toFixed(3),3.toFixed(3)) it gets unreadable and it would be undeniably nicer to do this for smaller precisions: randy(2.000,3.000).
Is this possible?
Fiddle

There is a clever way to solve this problem , is to define a class that helps you managing the number values and the decimal values.
function HappyNumber()
{
this.value = (typeof(arguments[0]) == "number") ? arguments[0] : 0;
this.decimal = (typeof(arguments[1]) == "number") ? arguments[1] : 0;
this.Val = function()
{
return parseFloat(this.value.toFixed(this.decimal));
}
this.toString = function()
{
return (this.value.toFixed(this.decimal)).toString();
}
}
How this class works
Now first thing to do is to create a new number like this
var Num = HappyNumber(4.123545,3);
// first argument is the value
// and second one is decimal
To get the value of your variable, you should use the function Val like this
console.log(Num.Val()); // this one prints 4.123 on your console
The most important part is this one, when you use the toString function it return your number
Num.toString() // it returns "4.123"
(new HappyNumber(4,4)).toString(); // it returns "4.0000"
Now you pass arguments as (HappyNumber), and inside your function use toString and it returns the right value you need and it works with numbers like 1.00 2.000 4.00000

This will do what you want. (Warning: This is probably not a good idea.)
Number.prototype.toString = function () { return this.toFixed(1); }

Evaluating numbers that include thousand separators

I understand that if the parseFloat function encounters any character other than numeric characters (0-9+-. and exponents) it just evaluates the number up to that character, discarding anything else.
I'm having a problem where I need to be able to validate numbers with thousand separators like so:
var number = "10,000.01"; //passes
var numberWithoutThousand = "10000.01"; //fails
//i.e:
if(parseFloat(number) <= 10000) {
return true;
}
//passess
problem is the above code returns true when technically that number is larger than 10,000.
What's the best way to get around this? I've considered stripping out the comma before testing the number, but not sure that is a good strategy.

You don't have numbers, you have strings, so just removing the comma is the way to go
number = number.replace(/\,/g, '');

Your "stripping the comma" strategy seems good to me.
if ( parseFloat( number.replace(",","") ) ) { etc(); }

As has been suggested, to have , in the number it must be a string and so do a search and replace. If you are having to do this on a regular basis then make yourself a reusable function.
Javascript
function myParseFloat(value) {
if (typeof value === 'string') {
value = value.replace(/,/g, '');
}
return parseFloat(value);
}
var number1 = "10,000.01",
number2 = "10000.01",
number3 = 10000.01;
console.log(myParseFloat(number1), myParseFloat(number2), myParseFloat(number3));
Output
10000.01 10000.01 10000.01
On jsFiddle

Show numbers to second nearest decimal

I'm very new to Javascript so please bear with me.
I have this function that adds up a total. How do I make it so that it shows the nearest two decimal places instead of no decimal places?
function calcProdSubTotal() {
var prodSubTotal = 0;
$(".row-total-input").each(function() {
var valString = $(this).val() || 0;
prodSubTotal += parseInt(valString);
});
$("#product-subtotal").val(CommaFormatted(prodSubTotal));
}
Thank you!
Edit: As requested: commaFormatted:
function CommaFormatted(amount) {
var delimiter = ",";
var i = parseInt(amount);
if(isNaN(i)) { return ''; }
i = Math.abs(i);
var minus = '';
if (i < 0) { minus = '-'; }
var n = new String(i);
var a = [];
while(n.length > 3)
{
var nn = n.substr(n.length-3);
a.unshift(nn);
n = n.substr(0,n.length-3);
}
if (n.length > 0) { a.unshift(n); }
n = a.join(delimiter);
amount = "$" + minus + n;
return amount;
}

Well parseInt parses integers, so you are getting rid of any decimals right there. Use parseFloat.
E.g.
parseFloat('10.599').toFixed(2); //10.60
You might also want to change your commaFormatted function to something like:
function commaFormatted(amount) {
if (!isFinite(amount) || typeof amount !== 'number') return '';
return '$' + amount.toFixed(2).replace(/(\d)(?=(\d{3})+(?!\d))/g, '$1,');
}
commaFormatted(0); //$0.00
commaFormatted(1.59); //$1.59
commaFormatted(999999999.99); //$999,999,999.99

Use to function toFixed(2)
The 2 is an integer parameter that says use 2 decimal points, assuming your comma formatted code does not turn it into a string. (If it does, fix the decimals BEFORE you run it through the formatting)
$("#product-subtotal").val(CommaFormatted(parseFloat(prodSubTotal).toFixed(2)));
Remember to parseFloat because the val() could be a string!`

You're looking for toFixed(). It takes one parameter, digits. The parameter is documented as follows:
The number of digits to appear after the decimal point; this may be a value between 0 and 20, inclusive, and implementations may optionally support a larger range of values. If this argument is omitted, it is treated as 0.
Do also note that parseInt() parses integers, truncating any decimals you might have. parseFloat() will preserve decimals as expected.

I solved my problem. I simply changed:
$("#product-subtotal").val(CommaFormatted(prodSubTotal));
to
$("#product-subtotal").val(prodSubTotal);
As I stated in the comments, this was not a script I wrote. It is a script Chris Coyier wrote and I was just trying to amend it. I guess I didn't need to use CommaFormatted for my purposes?
Thank you all for your help!

Javascript string/integer comparisons

I store some parameters client-side in HTML and then need to compare them as integers. Unfortunately I have come across a serious bug that I cannot explain. The bug seems to be that my JS reads parameters as strings rather than integers, causing my integer comparisons to fail.
I have generated a small example of the error, which I also can't explain. The following returns 'true' when run:
console.log("2" > "10")

Parse the string into an integer using parseInt:
javascript:alert(parseInt("2", 10)>parseInt("10", 10))

Checking that strings are integers is separate to comparing if one is greater or lesser than another. You should always compare number with number and string with string as the algorithm for dealing with mixed types not easy to remember.
'00100' < '1' // true
as they are both strings so only the first zero of '00100' is compared to '1' and because it's charCode is lower, it evaluates as lower.
However:
'00100' < 1 // false
as the RHS is a number, the LHS is converted to number before the comparision.
A simple integer check is:
function isInt(n) {
return /^[+-]?\d+$/.test(n);
}
It doesn't matter if n is a number or integer, it will be converted to a string before the test.
If you really care about performance, then:
var isInt = (function() {
var re = /^[+-]?\d+$/;
return function(n) {
return re.test(n);
}
}());
Noting that numbers like 1.0 will return false. If you want to count such numbers as integers too, then:
var isInt = (function() {
var re = /^[+-]?\d+$/;
var re2 = /\.0+$/;
return function(n) {
return re.test((''+ n).replace(re2,''));
}
}());
Once that test is passed, converting to number for comparison can use a number of methods. I don't like parseInt() because it will truncate floats to make them look like ints, so all the following will be "equal":
parseInt(2.9) == parseInt('002',10) == parseInt('2wewe')
and so on.
Once numbers are tested as integers, you can use the unary + operator to convert them to numbers in the comparision:
if (isInt(a) && isInt(b)) {
if (+a < +b) {
// a and b are integers and a is less than b
}
}
Other methods are:
Number(a); // liked by some because it's clear what is happening
a * 1 // Not really obvious but it works, I don't like it

Comparing Numbers to String Equivalents Without Using parseInt
console.log(Number('2') > Number('10'));
console.log( ('2'/1) > ('10'/1) );
var item = { id: 998 }, id = '998';
var isEqual = (item.id.toString() === id.toString());
isEqual;

use parseInt and compare like below:
javascript:alert(parseInt("2")>parseInt("10"))

Always remember when we compare two strings.
the comparison happens on chacracter basis.
so '2' > '12' is true because the comparison will happen as
'2' > '1' and in alphabetical way '2' is always greater than '1' as unicode.
SO it will comeout true.
I hope this helps.

You can use Number() function also since it converts the object argument to a number that represents the object's value.
Eg: javascript:alert( Number("2") > Number("10"))

+ operator will coerce the string to a number.
console.log( +"2" > +"10" )

The answer is simple. Just divide string by 1.
Examples:
"2" > "10" - true
but
"2"/1 > "10"/1 - false
Also you can check if string value really is number:
!isNaN("1"/1) - true (number)
!isNaN("1a"/1) - false (string)
!isNaN("01"/1) - true (number)
!isNaN(" 1"/1) - true (number)
!isNaN(" 1abc"/1) - false (string)
But
!isNaN(""/1) - true (but string)
Solution
number !== "" && !isNaN(number/1)

The alert() wants to display a string, so it will interpret "2">"10" as a string.
Use the following:
var greater = parseInt("2") > parseInt("10");
alert("Is greater than? " + greater);
var less = parseInt("2") < parseInt("10");
alert("Is less than? " + less);