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denoland-deno/std/bytes/README.md

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# bytes
bytes module is made to provide helpers to manipulation of bytes slice.
# usage
All the following functions are exposed in `mod.ts`
## findIndex
Find first index of binary pattern from given binary array.
```typescript
import { findIndex } from "https://deno.land/std/bytes/mod.ts";
findIndex(
new Uint8Array([1, 2, 0, 1, 2, 0, 1, 2, 0, 1, 3]),
new Uint8Array([0, 1, 2]),
);
// => returns 2
```
## findLastIndex
Find last index of binary pattern from given binary array.
```typescript
import { findLastIndex } from "https://deno.land/std/bytes/mod.ts";
findLastIndex(
new Uint8Array([0, 1, 2, 0, 1, 2, 0, 1, 3]),
new Uint8Array([0, 1, 2]),
);
// => returns 3
```
## equal
Check whether given binary arrays are equal to each other.
```typescript
import { equal } from "https://deno.land/std/bytes/mod.ts";
equal(new Uint8Array([0, 1, 2, 3]), new Uint8Array([0, 1, 2, 3])); // returns true
equal(new Uint8Array([0, 1, 2, 3]), new Uint8Array([0, 1, 2, 4])); // returns false
```
## hasPrefix
Check whether binary array has binary prefix.
```typescript
import { hasPrefix } from "https://deno.land/std/bytes/mod.ts";
hasPrefix(new Uint8Array([0, 1, 2]), new Uint8Array([0, 1])); // returns true
hasPrefix(new Uint8Array([0, 1, 2]), new Uint8Array([1, 2])); // returns false
```
## repeat
Repeat bytes of given binary array and return new one.
```typescript
import { repeat } from "https://deno.land/std/bytes/mod.ts";
repeat(new Uint8Array([1]), 3); // returns Uint8Array(3) [ 1, 1, 1 ]
```
## concat
Concatenate two binary arrays and return new one.
```typescript
import { concat } from "https://deno.land/std/bytes/mod.ts";
concat(new Uint8Array([1, 2]), new Uint8Array([3, 4])); // returns Uint8Array(4) [ 1, 2, 3, 4 ]
```
## copyBytes
Copy bytes from one binary array to another.
```typescript
import { copyBytes } from "https://deno.land/std/bytes/mod.ts";
const dst = new Uint8Array(4);
const src = Uint8Array.of(1, 2, 3, 4);
const len = copyBytes(src, dest); // returns len = 4
```