Regular Expressions 101

Negative Lookbehind(?<!\d|-|\/|to|\$)

1st Alternative\d

\da digit

2nd Alternative-

-the literal - (45₁₀ / 55₈ / 2D₁₆)

3rd Alternative\/

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

4th Alternativeto

tothe literal text to (case sensitive)

5th Alternative\$

\$the literal $ (36₁₀ / 44₈ / 24₁₆)

Negative Lookbehind(?<!\$(\d)\.)

\$the literal $ (36₁₀ / 44₈ / 24₁₆)

Group 1(\d)

\da digit

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 2([1-9][0-9]{0,2}(\.\d{0,2})?\s?)

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

Character Class[0-9]{0,2}

{0,2}matches between 0 and 2 characters from the set below:

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

Group 3(\.\d{0,2})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d{0,2}a digit, repeated between 0 and 2 times

\s?optionally matches any whitespace character

Group 4(lbs|lb|LBS|LB|KG|kg|G|g|L|l+)

1st Alternativelbs

lbsthe literal text lbs (case sensitive)

2nd Alternativelb

lbthe literal text lb (case sensitive)

3rd AlternativeLBS

LBSthe literal text LBS (case sensitive)

4th AlternativeLB

LBthe literal text LB (case sensitive)

5th AlternativeKG

KGthe literal text KG (case sensitive)

6th Alternativekg

kgthe literal text kg (case sensitive)

7th AlternativeG

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

8th Alternativeg

gthe literal g (103₁₀ / 147₈ / 67₁₆) (case sensitive)

9th AlternativeL

Lthe literal L (76₁₀ / 114₈ / 4C₁₆) (case sensitive)

10th Alternativel+

l+the literal l (108₁₀ / 154₈ / 6C₁₆) (case sensitive), repeated at least once

Negative Lookahead(?!\d|\w)

1st Alternative\d

\da digit

2nd Alternative\w

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

Ready to run

26 tokens

Regular Expression

(?<!\d|-|\/|to|\$)(?<!\$(\d)\.)([1-9][0-9]{0,2}(\.\d{0,2})?\s?)(lbs|lb|LBS|LB|KG|kg|G|g|L|l+)(?!\d|\w)

Regular Expression

Unit Tests