What does “:=” do?

Question

I\'ve seen := used in several code samples, but never with an accompanying explanation. It\'s not exactly possible to google its use without knowing the proper

Answer 1

Colon-equals was used in Algol and its descendants such as Pascal and Ada because it is as close as ASCII gets to a left-arrow symbol.

The strange convention of using equals for assignment and double-equals for comparison was started with the C language.

In Prolog, there is no distinction between assignment and the equality test.