This question already has answers here:
Is floating point math broken?
(31 answers)
Closed 8 years ago.
I have a fiddle here: http://jsfiddle.net/94wQJ/1/ - but probably someone can advise just by looking below.
<button type="button" id="allocate">Calc</button>
$('#allocate').click(function () {
val1 = 25.00;
val2 = 16.37;
val3 = val1-val2;
alert(val3);
});
25 - 16.37 = 8.63 - however, the alert for val3 = 8.62999999999
Why is it not accurate?
Thank you,
Mark
Try Using toFixed more information here
val3.toFixed(2)
Demo Fiddle
Why is it not accurate?
This is a duplicate of Is floating point math broken?, but to answer your specific question: floating point numbers generally store the number in base 2 because it allows storing more numbers more accurately than using base 10, at the expense of not being able to exactly store all base 10 numbers even with a small number of decimal places.
Many decimal fractions not be represented exactly in binary.
Use .toFixed(2)
Please check this
val3 = Math.round(val3*100)/100;
I have update here http://jsfiddle.net/94wQJ/7/
Related
This question already has answers here:
How to deal with floating point number precision in JavaScript?
(47 answers)
Closed 1 year ago.
In my project, when I am subtracting 96.74 from 60, javascript is giving me 36.739999999999995 , but I need 36.74 to do further calculation.
What should I do, how do I overcome this problem??
Thanks in advance.
Use parseFloat and set the decimal places to 2 with .toFixed(2)
console.log(parseFloat(36.739999999999995).toFixed(2))
If you want to get rid of trailing zeroes cast the result to a Number:
var num = Number(parseFloat(36.7).toFixed(2));
console.log(num);
Example how to round to two decimals, if that was what you wanted?
var x = 36.739999999999995;
x = Math.round(x*Math.pow(10,2))/Math.pow(10,2);
console.log(x);
This question already has answers here:
Is floating point math broken?
(31 answers)
Closed 4 years ago.
var tm=110;
var fm=200;
var pr=Math.ceil(tm/fm*100);
console.log(pr);
The result is showing 56.
But it should be 55
Note that
tm/fm*100 is resulting 55.0000001
But
When tm=100 and all fm=200 then the result is 50
I've solved that problem concedering upto 2 decimal places after point, I could not understand where from 1 is comming after some 0s!
Math.ceil() returns the smallest integer greater than or equal to a given number. See MDN Documentation.
Remove Math.ceil()
parseFloat() pr variable
Call Float's precision method toPrecision(8)
The extra 1 you are seeing is a result of binary floating point math. JavaScript does this. Source
<script>
var tm=110;
var fm=200;
var pr= parseFloat(tm/fm*100);
alert(pr.toPrecision(8)); // output: 55.00000000
</script>
This question already has answers here:
How to format numbers as currency strings
(67 answers)
Closed 5 years ago.
I'm given numbers in cents:
eg.
102042
982123
121212
I want to convert them to dollars. I figured the easiest way to do this is to convert the digits into a string and add a decimal.
eg.
1020.42
9821.23
1212.12
I'm currently doing this but it only rounds to 1 decimal. What would I need to do it make it round to 2 decimals?
var number = 102042
number.toString().match(/^-?\d+(?:\.\d{0,2})?/)[0]
UPDATE: I found out what my issue was. It wasn't the rounding but the fact that I combined a lodash filter to a division incorrectly. Thanks again!
A cent is 1/100th of a dollar, so you can calculate the dollar amount by doing
dollars = number / 100
var number = 102042;
console.log(number/100);
The easiest way is to do it with the number itself, you can multiply by 0.01 or divide by 100 and you'll get that amount in dollars:
var numbers = [102042,982123,121212];
for(num of numbers)
console.log(num/100);
This question already has answers here:
Is floating point math broken?
(31 answers)
Closed 8 years ago.
The jQuery displays 12.123456789123003 instead of 12.123456789123 when this value 1212.3456789123 multiplies with 100.
Code:
<p class="price">12.123456789123</p>
<button>Calculate</button>
$(':button').click(function () {
$('p.price').text(function (i, v) {
return v * 100;
});
this.disabled = true;
});
Because of the non-exact nature of floating point values (this is not JavaScript's fault), you need to be more specific, i.e.:
$('p.price').text(function (i, v) {
return (v * 100).toFixed(10);
});
Where .toFixed(10) determines the desired size of your fraction.
JavaScript has problems with floating point numbers precision.
If you want precise results in JS, like when you working with money, you need use something like BigDecimal
There is 12 digits in decimal portion so when 12.123456789123 is multiplied by 100 1212.3456789123 doesn't contain the 12 digits so it's filling remaining numbers that's it.
This is a rounding error. Don't use floating-point types for currency values; you're better off having the price be in terms of the smallest integral unit. It's quite unusual to have prices be in precise units like that. If you really need to use a floating-point type, then use 1e-12 * Math.round(1e14 * v).
This question already has answers here:
How to deal with floating point number precision in JavaScript?
(47 answers)
Closed 8 years ago.
Tried :
var a=10.3;
var b=2.3;
alert(a+b);
but I get 12.600000000000001. I know JavaScript is loosely typed, but I hope I can do a sum :)
you can use toFixed() method also
var a=10.3;
var b=2.3;
alert((a+b).toFixed(1));
Works in chrome
Multiply to the precision you want then round and divide by whatever you multiplied by:
var a=10.3;
var b=2.3;
alert(Math.round((a+b) * 10) / 10);
http://jsfiddle.net/DYKJB/3/
It's not about the typing but about the precision of floating point types. You need to round for presentation.
Floating point types are not a good choice if you need exact values. If you want to express currency values express them as cents or use an appropriate library for this.