Course of Raku / Regexes and grammars / Regexes / Quantifiers / Exercises / An optional sign

Solution: An optional sign

Here is a possible solution to the task.

Code

say '-42' ~~ / '-'? \d+ /;

🦋 You can find the source code in the file optional-sign.raku.

Output

｢-42｣

Comments

1. The '-'? part matches an optional minus sign — zero or one of them.

2. \d+ then matches the run of digits. The same pattern also matches a number with no sign, such as 42.

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