What is a buffer in Node.js?

Question

As you can read in the Node.js documentation on the Buffer class, a buffer

is similar to an array of integers but corresponds to a raw memory allocation outside the V8 heap.

So far, so good.

What now puzzles me is the question what a buffer is technically speaking. Is it an array with just some additional functions for creating and converting to strings using specific encodings?

Or is there "more" to it?

Answer 1

A Buffer is a chunk of memory, just like you would have it in C/C++. You can interpret this memory as an array of integer or floating point numbers of various lengths, or as a binary string. Unlike higher-level data structures like arrays, a buffer is not resizable.

It corresponds roughly to:

• char* or char[] in C/C++
• byte[] in Java
• A mutable bytes or a non-resizable bytearray in Python
• Strings in php if they were mutable

Answer 2

BUFFER is a temporary holding spot for data being moved from one place to another.

In order to understand what is Buffer, we need to know how a computer will process things. See the chart below.

The concept is like if you are watching a Youtube Video, you can start to watch a video without downloading the whole video. If your internet speed is too slow, you would see "buffering", that means the computer is trying to collect data in order for you to keep watching that video.