what is means this symbols /[+]+/g? [closed]

The following code uses the regular expression /[+]+/g,. I want to know how the code works and what the expression does.[] will match one of the characters found in the set, ^ means to match anything that’s not in the set, and then d|-+|.+ mean any digit (that’s the d), |, -, +, ., and a couple characters that were repeated.