The **``Buffer.alloc`` function** is part of the Buffer module in Node.js and is used to allocate a buffer of any size less than the constant value of `buffer.constants.MAX_LENGTH`.
# Syntax
 ```node.js
Buffer.alloc(length, value, encoding);
```
# Parameters
The ``Buffer.alloc`` function takes up to three arguments:
* **`length`**: the length of the buffer.
* **`value`**: the value to be stored in the buffer. The value is replicated to fill the buffer.

* **`encoding`**: the encoding of the value. If the value is a string, the encoding is assumed to be `utf8` by default.

> Only `length` is a required parameter; the other two are optional parameters.

The ``Buffer.alloc`` function supports the following encoding types:

# Return value
If the size of `length` is greater than `buffer.constants.MAX_LENGTH` or smaller than 0, the error `ERR_INVALID_ARG_VALUE` is raised. The function does not return anything otherwise.

# Example
The following code snippet below shows how to allocate a buffer of size *15* and in `hex` encoding. The value is in base 10. In `hex`, *88* converts to *58*. The buffer is shown as output in the console, using the ``console.log`` function.

var buf = Buffer.alloc(15, 88, "hex");
console.log(buf);

Here, the prescribed value is of type ``string``. Hence, the encoding has been selected as `utf-8` by default. Since the value of the character `e` is *65* in ``hex``, the buffer is filled with *20* values of *65*. Note that *20* is the prescribed length of the buffer.

var buf = Buffer.alloc(20, 'e');
console.log(buf);

What is Buffer.alloc in Node.js?

The Buffer.alloc function in Node.js allocates buffers, requiring only length and offering optional value and encoding parameters.