/JavaScript

# BigInt.asIntN()

The `BigInt.asIntN` static method clamps a `BigInt` value to the given number of bits, and returns that value as a signed integer.

## Syntax

```BigInt.asIntN(bits, bigint);
```

### Parameters

`bits`

The amount of bits available for the integer size.

`bigint`

The BigInt value to clamp to fit into the supplied bits.

### Returns

The value of `bigint` modulo 2^`bits`, as a signed integer.

## Description

The `BigInt.asIntN` method clamps a `BigInt` value to the given number of bits, and interprets the result as a signed integer. For example, for `BigInt.asIntN(3, 25n)`, the value `25n` is clamped to `1n`:

```25n = 00011001 (base 2)
^=== Clamp to three remaining bits
===>       001 (base 2) = 1n
```

If the leading bit of the remaining number is `1`, the result is negative. For example, `BigInt.asIntN(4, 25n)` yields `-7n`, because `1001` is the encoding of `-7` under two's complement:

```25n = 00011001 (base 2)
^==== Clamp to four remaining bits
===>      1001 (base 2) = -7n
```

Note: `BigInt` values are always encoded as two's complement in binary.

## Examples

### Staying in 64-bit ranges

The `BigInt.asIntN()` method can be useful to stay in the range of 64-bit arithmetic.

```const max = 2n ** (64n - 1n) - 1n;

BigInt.asIntN(64, max);
// ↪ 9223372036854775807n

BigInt.asIntN(64, max + 1n);
// ↪ -9223372036854775808n
// negative because the 64th bit of 2^63 is 1
```

## Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
`asIntN`
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