Hello world is the beginning of everything. When you first learn a new programming language, the first program you write is to print the "Hello world" string on the console with that language. For example:
So who invented "Hello world"? It's Brian Kernighan, a canadian computer scientist and author of The C Programming Language and The Unix Programming Environment. In his books, he used to write "Hello world" which changed the whole world.
Also programmers like to use foo and bar as variable names, weird names.
Actually, beyond programming, other fields also have "Hello world" phenomenon.
For example, in typography, we often see:
"The quick brown fox jumps over the lazy dog" is the "Hello world" of typography.
The above one is the "Hello world" of image.
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