Node.js Buffer.alloc() Method

Create a 15 bytes buffer object:

var buf = Buffer.alloc(15);
console.log(buf);

Definition and Usage

The Buffer.alloc() method creates a new buffer object of the specified size.

Buffer.alloc(size, fill, encoding);

Parameter	Description
size	Required. Specifies the size of the buffer
fill	Optional. Specifies a value to fill the buffer with if specified, otherwise the buffer is filled with 0 (zero-filled)
encoding	Optional. If the buffer values are strings, this parameter specifies the encoding, default encoding is utf8. Supported values are: "ascii" "utf8" "utf16le" "ucs2" "base64" "latin1" "binary" "hex"

Return Value:	None
Node.js Version:	5.10.0

Using the fill parameter:

var buf = Buffer.alloc(15, 'a');
console.log(buf);