Regular Expressions 101

^start of line

Negative Lookahead(?!^0(e[0-9]|[EPTGMK]i?|)$)

^start of line

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Group 1(e[0-9]|[EPTGMK]i?|)

1st Alternativee[0-9]

ethe literal e (101₁₀ / 145₈ / 65₁₆) (case sensitive)

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

2nd Alternative[EPTGMK]i?

Character Class[EPTGMK]

Ethe literal E (69₁₀ / 105₈ / 45₁₆) (case sensitive)

Pthe literal P (80₁₀ / 120₈ / 50₁₆) (case sensitive)

Tthe literal T (84₁₀ / 124₈ / 54₁₆) (case sensitive)

Gthe literal G (71₁₀ / 107₈ / 47₁₆) (case sensitive)

Mthe literal M (77₁₀ / 115₈ / 4D₁₆) (case sensitive)

Kthe literal K (75₁₀ / 113₈ / 4B₁₆) (case sensitive)

i?optionally matches the literal i (105₁₀ / 151₈ / 69₁₆) (case sensitive)

3rd Alternative — matches an empty string

$end of line

Group 2([0-9]+)

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

Group 3(|[EPTGMK]i?|e[0-9]+)

1st Alternative — matches an empty string

2nd Alternative[EPTGMK]i?

Character Class[EPTGMK]

Ethe literal E (69₁₀ / 105₈ / 45₁₆) (case sensitive)

Pthe literal P (80₁₀ / 120₈ / 50₁₆) (case sensitive)

Tthe literal T (84₁₀ / 124₈ / 54₁₆) (case sensitive)

Gthe literal G (71₁₀ / 107₈ / 47₁₆) (case sensitive)

Mthe literal M (77₁₀ / 115₈ / 4D₁₆) (case sensitive)

Kthe literal K (75₁₀ / 113₈ / 4B₁₆) (case sensitive)

i?optionally matches the literal i (105₁₀ / 151₈ / 69₁₆) (case sensitive)

3rd Alternativee[0-9]+

ethe literal e (101₁₀ / 145₈ / 65₁₆) (case sensitive)

Character Class[0-9]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

$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.

Search reference

Regular Expression

^(?!^0(e[0-9]|[EPTGMK]i?|)$)([0-9]+)(|[EPTGMK]i?|e[0-9]+)$

New

0K
0Ki
0
0e0

1K
10K
100K
1000Ki

1Ki
10Ki
100Ki
1000Ki

1
10
100
1000

1e0
1e1
10e10
100e100

Regular Expression

Substitution