How do I display whole number in JavaScript? [duplicate]

Question

This question already has answers here:

How to avoid scientific notation for large numbers in JavaScript? (25 answers)

Closed 8 years ago.

Let's say I write this in JS:

var product = 50000000*39048902222211111111111111111111:
alert(product); //this gives me 1.9524451111105555e+39.

Is there any way to display the whole number, and not that e+39 thing?

Answer 1

The integer values you are trying to represent are larger than the integer precision that Javascript can handle (fixed-precision arithmetic). Maximum safe integers are -9007199254740991 to 9007199254740991 or +/-(2^53-1)

While 9007199254740992 can be represented it is considered unsafe. Why? Try this jsFiddle

Javascript

alert(9007199254740992 + 1);

Output

9007199254740992

See specification ecma-262/5.1/#sec-8.5

But you can use a library for arbitrary-precision arithmetic, or roll your own.

Using one such library, bignumber.js, loaded using require.js

Javascript

require.config({
    paths: {
        bignumberjs: 'https://raw.github.com/MikeMcl/bignumber.js/master/bignumber.min'
    }
});

require(['bignumberjs'], function (BigNumber) {
    BigNumber.config({
        EXPONENTIAL_AT: 100
    });

    var product = new BigNumber('50000000').times('39048902222211111111111111111111');

    alert(product);

});

Output

1952445111110555555555555555555550000000

On jsFiddle

Answer 2

Try somthing like this:

Number.prototype.realValue = function(){
    return this.toString().replace(/^([+-])?(\d+).?(\d*)[eE]([-+]?\d+)$/, function(x, s, n, f, c){
        var l = +c < 0, i = n.length + +c, x = (l ? n : f).length,
        c = ((c = Math.abs(c)) >= x ? c - x + l : 0),
        z = (new Array(c + 1)).join("0"), r = n + f;
        return (s || "") + (l ? r = z + r : r += z).substr(0, i += l ? z.length : 0) + (i < r.length ? "." + r.substr(i) : "");
    });
};

Acess the medthod like:

var product = 50000000*39048902222211111111111111111111:
alert(product.realValue())

Sources:Javascript display really big numbers rather than displaying xe+n