Meet BigInt, New Features of ECMAScript 2020

BigInt is a native JavaScript object that provides a model of representation of integers larger than, which is the largest number that JavaScript can accurately represent, using the primitive type Number. ECMAScript 2020 - The Future and Beyond.

Syntax:

BigInt’s syntax is:

BigInt(value);

Where:

value: is the numeric value of the object that will be created. This can be a string or an integer.

It is important to note that BigInt() is not used with the new operator.

BigInt is created by simply adding an “n” to the end of a literal integer - 10n - or by calling function BigInt();

const theBiggestInt = 9007199254740991n;
const alsoHuge = BigInt(9007199254740991);
// 9007199254740991n
const hugeString = BigInt("9007199254740991");
// 9007199254740991n
const hugeHex = BigInt("0x1fffffffffffff");
// 9007199254740991n
const hugeBin = BigInt("0b11111111111111111111111111111111111111111111111111111");
// 9007199254740991n

BigInt differs from Number in some important matters. For example:

It cannot be used with methods on the Math object;
It cannot be mixed into operations or any Number instance. They must be handled with the same type.
BigInt’s accuracy can be lost by converting values to Number.

If you want to run some tests, you can:

Testing with typeof:

typeof 1n === 'bigint'; // true
typeof BigInt('1') === 'bigint'; // true

If it is involved in an Object, BigInt will be considered as a normal type of “object”:

typeof Object(1n) === 'object'; // true

You can also perform operations with BigInt or with BigInt involved in an object:

const antigoMaximoInt = BigInt(Number.MAX_SAFE_INTEGER);
// 9007199254740991
const maximoMaisUm = antigoMaximoInt + 1n;
// 9007199254740992n
const oFuturo= antigoMaximoInt + 2n;
// 9007199254740993n, isso funciona agora!
const multiplicando = antigoMaximoInt * 2n;
// 18014398509481982n
const subtraindo = multiplicando – 10n;
// 18014398509481972n
const modulo = multiplicando % 10n;
// 2n
const bigN = 2n ** 54n;
// 18014398509481984n
bigN * -1n
// –18014398509481984n

Note:

The/operator also works. However, if the numbers are BigIntS and not BigDecimalS, the operation will be rounded to zero, which will not bring us any fractional value.

const divisao = 4n / 2n;
// 2n
const arredondado = 5n / 2n;
// 2n, e não 2.5n

It is important to note that BigInt is not strictly the same as a Number, but they can be compared normally.

0n === 0;
// false
0n == 0;
// true
1n < 2;
// true
2n > 1;
// true
2 > 2;
// false
2n > 2;
// false
2n >= 2;
// true

BigInt behaves like a number when it is converted to a Boolean, and can also be used with logical operators, also within a conditional structure.

if (0n) {
    console.log("Olá, você está dentro do IF");
} else {
    console.log("Olá, você está dentro do ELSE");
}
0n || 12n;
// 12n
0n && 12n;
// 0n
Boolean(0n);
//  false
!0n;
// true

Properties:

BigInt.prototype;

Allows the addition of properties to a BigInt object. All BigInt instances are inherited from BigInt.prototype. The prototype object of the BigInt constructor can be modified to affect all instances of BigInt.

#ecmascript #bigint #javascript #ecmascript2020

Meet BigInt, New Features of ECMAScript 2020 - The Future and Beyond

Syntax:

Where:

Note:

Properties: