Javascript slice function returning different values for same value?

Question

im solving a question on hackerrank and i encountered a problem. my slice method is not returning the right value. I was able to recreate using console.log.

 console.log(+("9007199254740993")); console.log("9007199254740993");

why do these return different values?

Answer 1

The biggest value possible for a JavaScript number is 9007199254740991 .

To deal with numbers larger than that you will need to use a BigInt .

 const max = Number.MAX_SAFE_INTEGER; console.log(max); const maxPlusTwo = max + 2; console.log(maxPlusTwo); const maxPlusTwoBigInt = BigInt("9007199254740993"); console.log(maxPlusTwoBigInt.toString());

This link shows the current level of native support for BigInt. Depending on your target platform you may need to use a polyfill for BigInt functionality.

Answer 2

JavaScript has a maximum safe integer limit of 2^53 - 1 ( 9,007,199,254,740,991 ) - it is possible to have numbers greater than this, but it's not very good:

 console.log(9007199254740992 + 200000000001); console.log(Number.MAX_SAFE_INTEGER);

(The above snippet shows they are different - look at the fifth and last digits).

You would have to use an experimental BigInt if you wanted bigger numbers.