Regular Expressions 101

Explanation

Pro

^start of line

Negative Lookahead(?!.*([os])(?:.*\1){1})

.*any character (except for line terminators), repeated any number of times

Group 1([os])

Character Class[os]

othe literal o (111₁₀ / 157₈ / 6F₁₆) (case sensitive)

sthe literal s (115₁₀ / 163₈ / 73₁₆) (case sensitive)

Non-Capturing Group(?:.*\1){1}

{1}repeats the group contents below exactly 1 time:

.*any character (except for line terminators), repeated any number of times

\1the text saved by group 1

Negative Lookahead(?!.*([p])(?:.*\2){2})

.*any character (except for line terminators), repeated any number of times

Group 2([p])

Character Class[p]

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

Non-Capturing Group(?:.*\2){2}

{2}repeats the group contents below exactly 2 times:

.*any character (except for line terminators), repeated any number of times

\2the text saved by group 2

Character Class[pos]+

+matches at least one character from the set below:

pthe literal p (112₁₀ / 160₈ / 70₁₆) (case sensitive)

othe literal o (111₁₀ / 157₈ / 6F₁₆) (case sensitive)

sthe literal s (115₁₀ / 163₈ / 73₁₆) (case sensitive)

$end of line

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

^(?!.*([os])(?:.*\1){1})(?!.*([p])(?:.*\2){2})[pos]+$

New

pop
sop
ps
pops
poop
p
pp
ppp
pppp
o
oo
s
ss
popp
ppos