line edit validator number regex

user4592357

i need to have validator on my line edit.
the format of the acceptable input is as following: list of <number>s, or list of <number-number>s, or list of both, e.g. 4-8 10 34-100 222
i have compiled the following regexp: ([1-9]\d*(-[1-9]\d*)?\s*)+
but it falsely allows 5-55-55-55-555, while i need just 5-55 and not allow hyphen after second number
what's the correct regex to use?

SGaist

Hi,

You are over-engineering it:

R"^(\d+|\d+-\d+)$"

Should do it

user4592357

@SGaist
sorry, i forgot to mention, i need only positive numbers.
and that regex works for just one item, but i need to validate a list.

JonB

@user4592357
@SGaist's pattern does not allow negative numbers. For a space-separated list, you could go for, say:

R"^((\d+|\d+-\d+) *)+$"

There are other ways, depending on whether you need captures.

user4592357

@JonB
i need to exclude 0 as a number or range's start value, or a number starting with 0.

will that pattern prevent inputting the case i mentioned in original post? (sorry i'm away from computer right now).

JonB

@user4592357
So replace each \d token with something like ([1-9]\d*).

If you want to start putting more constraints on, like say in the \d+-\d+ case you might want the right hand number to be greater than the the left hand one, it's time to pull out the matches and do some numeric comparisons in a more advanced validation.

user4592357

@JonB
yes sure I will replace the numbers.
i just need to make sure that i the 5-55-55-55 pattern is prohibited by that regex, is it?

JonB

@user4592357
You want me to test it for you?! Start using an on-line resource to design & test the reg exs you want to use, e.g. https://regex101.com/ .

SGaist

You also have the regular expression tool that you can build and will give you the exact string you need in your code.

JonB

@SGaist
Excellent. But @user4592357 will probably have to return to his computer to achieve that :)

user4592357

@SGaist @JonB
thanks for all info.
unfortunately, ^((\d+|\d+-\d+) *)+$ regex still allows hyphen after 5-555.
i just need to regexp validator for my input, nothing to match for now.

JonB

@user4592357 said in line edit validator number regex:

unfortunately, ^((\d+|\d+-\d+) *)+$ regex still allows hyphen after 5-555.

Pardon?
5-555- gives Your regular expression does not match the subject string..

Instead of making us guess what input you have in mind, could you please test with one of the reg ex validators we referenced and paste precisely what string you claim it does/does not match?

ODБOï

hi
@JonB said in line edit validator number regex:

5-555- gives Your regular expression does not match the subject string..

If you write another number after the "5-555-" , then it will be accepted, ex : 5-555-8
OP only wants to accept groupes of 2 numbers separated by a hyphen.

JonB

@LeLev
Then I wish he had said so and given such an example, instead of

still allows hyphen after 5-555.

I will look at this now and offer an alternative in a few minutes time...
...like either of:

^((\d+|\d+-\d+)\b *)+$

^(\d+(-\d+)?\b *)+$

user4592357

@JonB
thanks!
anyways, i wanna understand why the regex with \b allows 55-555-? how does it match/validate?
because for that same string, the line edit's hasAcceptableInput() returns false.

JonB

@user4592357

anyways, i wanna understand why the regex with \b allows 55-555-? how does it match/validate?

Neither of the two regexs I have given with \b allow 55-555-. As tested at rex101.com.

I am finding your questions/statements very hard to comprehend....

user4592357

@JonB
sorry, i mean with previous (((\d+|\d+-\d+) *)+) regex, the validator allowed 55-555-.
which part of the regex string did match with the hyphen after 55-555? i want to understand the logic for matching it.

JonB

@user4592357
So when you said

why the regex with \b allows

you meant

why the regex without \b allows

! :)

Regex: ^((\d+|\d+-\d+) *)+$
Input: 5-555-8

You want to know why the input does match here. That's because in order to force a match if it possibly can, which is how reg exs work, this gets treated as though it were:
5-55 5-8
i.e. two separate digits-digits sequences. So I put in the \b word-boundary token in ^((\d+|\d+-\d+)\b *)+$ to prevent it splitting in the middle of a sequence of consecutive digits.

user4592357

@JonB
ok got it, thanks for explanation!