Regular Expressions 101

1st Alternative\b(?:key1|key2)\b:?(?:\h+|$)

\ban ASCII word boundary

Non-Capturing Group(?:key1|key2)

1st Alternativekey1

key1the literal text key1 (case sensitive)

2nd Alternativekey2

key2the literal text key2 (case sensitive)

\ban ASCII word boundary

:?optionally matches the literal : (58₁₀ / 72₈ / 3A₁₆)

Non-Capturing Group(?:\h+|$)

1st Alternative\h+

\h+any horizontal whitespace character, repeated at least once

2nd Alternative$

$end of line

2nd Alternative\b(?!(?:key1|key2)\b)[^\s:]+:

\ban ASCII word boundary

Negative Lookahead(?!(?:key1|key2)\b)

Non-Capturing Group(?:key1|key2)

1st Alternativekey1

key1the literal text key1 (case sensitive)

2nd Alternativekey2

key2the literal text key2 (case sensitive)

\ban ASCII word boundary

Negated Character Class[^\s:]+

+matches at least one character outside the set below:

\sany whitespace character

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

\b(?:key1|key2)\b:?(?:\h+|$)|\b(?!(?:key1|key2)\b)[^\s:]+:

New

aaa bbb ccc
aaa bbb key1:aaa ccc ddd
aaa bbb key2:aaa key1:bbb
aaa bbb key1 ccc
aaa bbb key1:xxx key2:
aaa bbb key1:  xxx ccc
aaa bbb key1  :xxx ccc
aaa bbb aakey1
aaa bbb key1aa
aaa bbb xxx:yyy zzz

Extraction

aaa bbb ccc
aaa bbb key1:aaa ccc ddd
aaa bbb key2:aaa key1:bbb
aaa bbb key1 ccc
aaa bbb key1:xxx key2:
aaa bbb key1:  xxx ccc
aaa bbb key1  :xxx ccc
aaa bbb aakey1
aaa bbb key1aa
aaa bbb xxx:yyy zzz