RegexdrillNegative lookbehind: positive numbers only
A regex exercise from Regexdrill. Solve it with a pattern box with live highlighting in your browser, checked against hidden test strings, and it is checked the moment you submit.
The task
Match every whole number that does not have a minus sign directly in front of it. Do not match the tail end of a negative number.
What this exercise teaches
(?<![-\d])\d+ refuses to start right after a minus or a digit, so -40 yields nothing instead of 0.
A hint if you get stuck
(?<!...) fails when the text behind matches. A digit behind the start means you are in the middle of a number.
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