JS number function adds up zeros at the end

Question

I am using the Number() JS function which is supposed to convert string value to numeric.

It's working fine for small numbers. For big ones - it is starting to substitude values with zeros as shown on the image:

Is there a work around for this problem?

score 2 · Answer 1 · answered Jul 20 '17 at 11:15

2

This is because you're using numbers that are larger than Number.MAX_SAFE_INTEGER and Javascript does not guarantee to represent these numbers correctly

Use Number.isSafeInteger to check:

> Number.isSafeInteger(Number('111111111111111111'))
< false

answered Jul 20 '17 at 11:15

user2314737

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Sankar · Accepted Answer · 2017-07-20T11:22:52.667

In JS, the largest integral value is 9007199254740991 That is, all the positive and negative integers should not exceed the -9007199254740991 and 9007199254740991 respectively.

The same is defined as the 2⁵³-1.

console.log(Number.isSafeInteger(parseInt('1111111111')))
console.log(parseInt('1111111111'))
console.log(Number.isSafeInteger(parseInt('111111111111111111')))
console.log(parseInt('111111111111111111'))
//9007199254740991 - The largest JS Number
console.log(Number.isSafeInteger(parseInt('9007199254740991')))

JS number function adds up zeros at the end

2 Answers2