This post covers a feature of numeric operators introduced in the latest JavaScript ECMAScript 2021.

These are only cosmetic changes in how we read the literals and numbers.

Numeric operators apply to numbers or literals allows developers to read them by separating a group of digits. _ or underscore symbol used as a separator.

For example,

if you are defining the number of One million as seen below

```
let result=1000000;
```

It is hard to read the number whether is one million or one lack thousand number.

The same number can be separated with _ as per your convenience in ES12.

```
let result=10_00_000;
```

**Valid Numeric separators**

Numeric separators are applied to number,**float**, **binary**, **hex**, **octal** and **bigint** literal types

Here is an example for floating literals

```
const floatNumber=10.23; // 10^10000
```

And also applied to **fraction** and **exponent** parts.

```
const exponentNumber=1e2_000; // 10^10000
```

Here is hexa,octal and binary literals example

```
const binaryNumber= 0b1110_0001_1010_0101; // binary number separation
const hexaNumber = 0xB1_C8_D1;
const octalNumber = 0o45_23_12;
```

big numbers in JavaScript represented in BigInt type

bigint numbers separated with numeric operators.

```
let TwoTrillion = 2_000_000_000_000n;
```

The following are invalid separators which throws an error

```
const floating1 = 4.54_35_; // SyntaxError
const invalid_separator = _1_000_000; // ReferenceError
```

Notes:

- _ applies to any digits between the numbers only.
- Starting and Ending digits can not be applied underscore.
- numeric digits are not separated not immediate before n in bigint literal types.