Regular Expressions 101

Explanation
Pro

Positive Lookahead(?=(1|2|3|4|5|6|7|8|9|one|two|three|four|five|six|seven|eight|nine))

Group 1(1|2|3|4|5|6|7|8|9|one|two|three|four|five|six|seven|eight|nine)

1st Alternative1

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2nd Alternative2

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

3rd Alternative3

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

4th Alternative4

4the literal 4 (52₁₀ / 64₈ / 34₁₆)

5th Alternative5

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

6th Alternative6

6the literal 6 (54₁₀ / 66₈ / 36₁₆)

7th Alternative7

7the literal 7 (55₁₀ / 67₈ / 37₁₆)

8th Alternative8

8the literal 8 (56₁₀ / 70₈ / 38₁₆)

9th Alternative9

9the literal 9 (57₁₀ / 71₈ / 39₁₆)

10th Alternativeone

onethe literal text one (case sensitive)

11th Alternativetwo

twothe literal text two (case sensitive)

12th Alternativethree

threethe literal text three (case sensitive)

13th Alternativefour

fourthe literal text four (case sensitive)

14th Alternativefive

fivethe literal text five (case sensitive)

15th Alternativesix

sixthe literal text six (case sensitive)

16th Alternativeseven

seventhe literal text seven (case sensitive)

17th Alternativeeight

eightthe literal text eight (case sensitive)

18th Alternativenine

ninethe literal text nine (case sensitive)

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

(?=(1|2|3|4|5|6|7|8|9|one|two|three|four|five|six|seven|eight|nine))

two1nine
eightwothree
abcone2threexyz
xtwone3four
4nineeightseven2
zoneight234
7pqrstsixteen

two1nine
eightwothree
abcone2threexyz
xtwone3four
4nineeightseven2
zoneight234
7pqrstsixteen