How to convert strings to bigInt in JavaScript

问题

I need to convert a string to BigInt like BigInteger in Javascript

Example

var reqId = "78099864177253771992779766288266836166272662";
var result = parseInt(reqId);
document.write(result);

Resultant value not matching since JavaScript only allows integers up to (2^53)-1.

Is there any way to overcome this?

回答1:

BigInt is now a native JavaScript language feature. It's at Stage 3 in the TC39 process and it's shipping in V8 v6.7 and Chrome 67.

To turn a string containing a valid numeric literal into a BigInt, use the global BigInt function:

const string = '78099864177253771992779766288266836166272662';
BigInt(string);
// 78099864177253771992779766288266836166272662n

If you just want to hardcode the numeric value into your code, there is no need to convert from a string; use a BigInt literal instead:

const value = 78099864177253771992779766288266836166272662n;

回答2:

You can use a JavaScript lib called BigInteger.js for the purpose.it is an arbitrary-length integer library for Javascript, allows arithmetic operations on integers of unlimited size, notwithstanding memory and time limitations.This lib can be download from this link.Like var largeNumber = bigInt("75643564363473453456342378564387956906736546456235345"); You can find documentation of lib here https://www.npmjs.com/package/big-integer

回答3:

You can use mathjs:

var reqId = "78099864177253771992779766288266836166272662";
var myBigNumber = math.bignumber(reqId);
var res = math.add(myBigNumber, 1);
console.log(myBigNumber.toString());
// 7.8099864177253771992779766288266836166272662e+43
console.log(res.toString());
// 7.8099864177253771992779766288266836166272663e+43

来源：https://stackoverflow.com/questions/36826748/how-to-convert-strings-to-bigint-in-javascript