PHP Regex: group must end with character but do not capture this character -

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example regex:

/^([\w]+:)?other:(.*)$/

example string:

test:other:words...

the first group match "test:", want capture "test". @ first thought:

/^([\w]+)?:?other:(.*)$/

but realised can't have single : in beginning. how can capture group if exists must end : : must not captured group?

example input , output:

randomstring:constantstring:somethingelse

should give 'randomstring' first group.

and

constantstring:somethingelse

should give first group empty

here go:

^(?:(\w+):)?constantstring:(.*)$

(?:) non capturing group

demo


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