RegEx for BMHT in a sequence

I am trying to build a regular expression. Abbreviations are as follows:

B - Billion
M - Million
T - Thousand开发者_如何学JAVA
H - Hundred

Now, If I say 3M2T it means 3 million 2 thousand But I cannot say 3T2M or I cannot say 3M2222T BMTH should be in a sequence and should follow standard rule to create a number. I went till this ([0-9]+[B]){1}+([0-9]+[M])?+([0-9]+[T])?+([0-9]+[H])? But here B is compulsary.

Please help.

Try this:

^(?:\d+B)?(?:\d{1,3}M)?(?:\d{1,3}T)?(?:\dH)?$

You can test it here regexr.com?2thld

(?:) is non capturing group, otherwise the captured part is stored in to a variable

\d is equal to [0-9]

? after a group or a character makes it optional

+ means one or more

{1,3} says at least once at most three occurrences

[M] is not needed when there is only 1 character then only M is enough

([0-9]{1,3}B)?([0-9]{1,3}M)?([0-9]{1,3}T)?([0-9]H)? Takes up to 3 digits for each B/M/T or 1 for H (in that order), each of the groups being optional. Add constraints suiting your needs… Take note that [0-9] is not necessarily equal to \d, it depends on regional settings and stuff.