nodemcu-firmware/docs/en/modules/encoder.md

# encoder Module

The encoder modules provides various functions for encoding and decoding byte data.

## encoder.toBase64()

Provides a Base64 representation of a (binary) Lua string.

#### Syntax
`b64 = encoder.toBase64(binary)`

#### Parameters
`binary` input string to Base64 encode

#### Return
A Base64 encoded string.

#### Example
```lua
print(encoder.toBase64(cyrpto.hash("sha1","abc")))
```

## encoder.fromBase64()

Decodes a Base64 representation of a (binary) Lua string back into the original string.

#### Syntax
`binary_string = encoder.toBase64(b64)`

#### Parameters
`b64` Base64 encoded input string 

#### Return
The decoded Lua (binary) string.

#### Example
```lua
print(encoder.fromBase64(encoder.toBase64("hello world")))
```

## encoder.toHex()

Provides an ASCII hex representation of a (binary) Lua string. Each byte in the input string is represented as two hex characters in the output.

#### Syntax
`hexstr = encoder.toHex(binary)`

#### Parameters
`binary` input string to get hex representation for

#### Returns
An ASCII hex string.

#### Example
```lua
print(encoder.toHex(crypto.hash("sha1","abc")))
```

## encoder.fromHex()

Provides a Lua binary string decode of a ASCII hex string. Each byte in the output string is represented as two hex characters in the input.

#### Syntax
`binary = encoder.toHex(hexstr)`

#### Parameters
`hexstr`  An ASCII hex string.

#### Returns
Decoded string of hex representation.

#### Example
```lua
print(encoder.fromHex("6a6a6a")))
```