String to Integer in Javascript

Question

this is code

const str = '1111';
console.log(Number(str));

But When String's length over 17, it will be have problem

const str = '111100000123121221234'
console.log(Number(str)); // 111100000123121220000

I want to know, what's the principle of convert string to Integer of Number Object. Why convert wrong

Thank You Very Much

You exceeded the maximum precision for integers in JS. That's why the number comes back "wrong". — Sirko, May 30 '18 at 13:20
Because that number is greater than MAX_SAFE_INTEGER(https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER) — Kavindra, May 30 '18 at 13:22

score 1 · Accepted Answer · answered May 30 '18 at 13:22

1

Because "Integers (numbers without a period or exponent notation) are accurate up to 15 digits". See: https://www.w3schools.com/js/js_numbers.asp

answered May 30 '18 at 13:22

Mikhail Zakharov

1 Answers1