Start of main content## Recommended snippets

Checks if two numbers are approximately equal to each other.

- Use
`Math.abs()`

to compare the absolute difference of the two values to`epsilon`

. - Omit the third argument,
`epsilon`

, to use a default value of`0.001`

.

```
const approximatelyEqual = (v1, v2, epsilon = 0.001) =>
Math.abs(v1 - v2) < epsilon;
```

`approximatelyEqual(Math.PI / 2.0, 1.5708); // true`

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### Number is negative zero

JavaScript, Math

Checks if the given value is equal to negative zero (

`-0`

).### Number is power of two

JavaScript, Math

Checks if the given number is a power of

`2`

.### Luhn check

JavaScript, Math

Implements the Luhn Algorithm, used to validate a variety of identification numbers.