Do you know the purpose of (^|\s) in the following expression?
/(^|\s)(apple|orange|lemon)(\s|$)/.test(foo);
Do you know the purpose of (^|\s) in the following expression? /(^|\s)(apple|orange|lemon)(\s|$)/.test(foo);
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Do you know the purpose of (^|\s) in the following expression?
/(^|\s)(apple|orange|lemon)(\s|$)/.test(foo);
(^|\s)matches the start of the string or a whitespace character.So it will match if the string says “apple it is”, or if it says “I want an apple”.
Do note that in the first case, it will match “apple “, and in the second case it matches ” apple”.
Notice the extra space matched. If that behaviour is not desired, then a word boundary should be used instead (given by
\b).Eg:
That would allow all apples matched to match “apple” exactly (instead of ” apple ” or other variants).