I need to write a regular expression for taking input like this
23,456,22,1开发者_运维技巧,32767
i.e.
- No commas allowed at the start or end.
- Spaces may come before and/or start of comma for e.g. 23, 45,56 ,67 etc.
- Ranges of each number should be 0-32767.
Currently I am using regular expression like this [0-9]+(,[0-9]+)*
.
This allows for numbers separated by commas only ( not allowing spaces at all), and it does not check for the range of number.
It's probably wise to do it in two steps. First check that the range is 0-99999:
^[0-9]{1,5}( *, *[0-9]{1,5})*$
Then parse the string to a list of integers using a general purpose programming language and check that x <= 32767
for each integer x.
You can validate a number range with a regex, but since you need to look at the textual representation of numbers, the regex will be hard to read:
0*(?:3276[0-7]|327[0-5][0-9]|32[0-6][0-9]{2}|3[01][0-9]{3}|[12][0-9]{4}|[1-9][0-9]{1,3}|[0-9])
matches an integer between 0 and 32767, with optional leading zeroes.
So your entire regex would be
^0*(?:3276[0-7]|327[0-5][0-9]|32[0-6][0-9]{2}|3[01][0-9]{3}|[12][0-9]{4}|[1-9][0-9]{1,3}|[0-9])(?: *, *0*(?:3276[0-7]|327[0-5][0-9]|32[0-6][0-9]{2}|3[01][0-9]{3}|[12][0-9]{4}|[1-9][0-9]{1,3}|[0-9]))*$
Now imagine you inherit that regex from a co-worker who has left your company years ago...Have fun :)
Therefore, take Mark's advice.
This answer is intended purely for educational purposes and does not constitute a recommendation to use a regex in this case.
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