dom events - Obtain two decimal places in JavaScript without rounding to the next bigger number - Stack Overflow

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I have this JS code:

var propertyYield = annualRent / propertyValue * 100.0;

In specific scenario the result is 4.999.

So when I do this

propertyYield.toFixed(2)

I'm getting propertyYield of 5.00.

What I want to achieve is to actually get 4.99 instead of 5.00 as rounding to two decimals.

How can I achieve that?

I have this JS code:

var propertyYield = annualRent / propertyValue * 100.0;

In specific scenario the result is 4.999.

So when I do this

propertyYield.toFixed(2)

I'm getting propertyYield of 5.00.

What I want to achieve is to actually get 4.99 instead of 5.00 as rounding to two decimals.

How can I achieve that?

• javascript
• dom-events

Share Improve this question Follow edited Aug 25, 2019 at 17:31 Brian Tompsett - 汤莱恩 5,8937272 gold badges6161 silver badges133133 bronze badges asked Jul 25, 2016 at 7:22 LazialeLaziale 8,2254848 gold badges155155 silver badges271271 bronze badges 2

• Check this thread which have similar problem statement stackoverflow./a/4912870/4948688 – Ritesh Kashyap Commented Jul 25, 2016 at 7:26
• Please check the article already discussed. Click here – Lovepreet Singh Commented Jul 25, 2016 at 7:34

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2 Answers 2

Sorted by: Reset to default 5

You could use Math.floor and some additional arithmetics:

Math.floor(15.7784514000 * 100) / 100

Or convert the number into a string, match the number up to the second decimal place and turn it back into a number:

Number(15.7784514000.toString().match(/^\d+(?:\.\d{0,2})?/))

Then you can still call toFixed to get a string with a fixed number of decimal places.

var num1 = Math.floor(15.7784514000 * 100) / 100;
console.log(num1);

var num2 = Number(15.7784514000.toString().match(/^\d+(?:\.\d{0,2})?/));
console.log(num2)
console.log(num2.toFixed(2))

Update: As noted by @kuka this does not work for certain decimal numbers due to floating point error math. Don't use this solution - However I'm leaving it here for documentation sake.

Not sure if I know a library method off hand to do that but quick simple old school solution would be this:

Math.floor(4.999 * 100) / 100.0

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