Golo Roden Golo Roden - 1 month ago 6x
Node.js Question

What is a buffer in Node.js?

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?


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