Using regexp to check for length of string that accepts optionalstrings

[-]

Is it possible to use regexp to check whether a string has a total
length of x characters if the string accepts optional parameters for e.g

[OptionalPrefix] VALUE [OptionalPostfix]

where each of the token can be of any length but the total length must
be less than x?

Is it possible or do I have to use:

if (string.matches(regexp) && string.length() < x) {
...
}

 

[Hemal Pandya]

Is it possible to use regexp to check whether a string has a total
length of x characters if the string accepts optional parameters for e.g

[OptionalPrefix] VALUE [OptionalPostfix]

where each of the token can be of any length but the total length must
be less than x?

Is it possible or do I have to use:

if (string.matches(regexp) && string.length() < x) {
...
}

You have to use string.length(). Just out of curiosity -- especially
since you are not even using a Pattern but directly using
String.matches -- what syntax (API) would you want to use to check the
total length using regexp?

 

[-]

You have to use string.length(). Just out of curiosity -- especially
since you are not even using a Pattern but directly using
String.matches

I am using a Pattern indirectly.

"An invocation of this method of the form str.matches(regex) yields
exactly the same result as the expression

Pattern.matches(regex, str)"

-- what syntax (API) would you want to use to check the

total length using regexp?

I don't grasp your question.

Just to clarify: I wanted to know whether regexp can check for the total
length of the string but as you mentioned, I have to use
String.length(). Hence I conclude that regexp cannot be used to check
the length. So I think the answer to your question is 'no syntax'.

 

[hiwa]

Is it possible to use regexp to check whether a string has a total
length of x characters if the string accepts optional parameters for e.g

[OptionalPrefix] VALUE [OptionalPostfix]

where each of the token can be of any length but the total length must
be less than x?

Is it possible or do I have to use:

if (string.matches(regexp) && string.length() < x) {
...
}

Quantifiers may or may not do you the service. Read the javadoc for
java.util.regex.Pattern class.

 

[Hemal Pandya]

I am using a Pattern indirectly.

Sorry. I meant to say you are not using Pattern _directly_. Since you
are using the String method, which checks if the /entire/ string
matches the pattern (and not that it contains a substring that matches
the pattern) I do not understand why you don't want to use the String
method.

"An invocation of this method of the form str.matches(regex) yields
exactly the same result as the expression

Pattern.matches(regex, str)"

-- what syntax (API) would you want to use to check the

I don't grasp your question.

/If/ it was possible to use regexp to check whether a string has a
total
length of x characters ; what API would you expect in regexp for this
purpose?

If you expect that method to be in String then String.length is that
method
If you expect that method to be in Pattern or in Matcher, I would argue
that it does not belong there.

 

[-]

Is it possible to use regexp to check whether a string has a total
length of x characters if the string accepts optional parameters for e.g

[OptionalPrefix] VALUE [OptionalPostfix]

where each of the token can be of any length but the total length must
be less than x?

Is it possible or do I have to use:

if (string.matches(regexp) && string.length() < x) {
...
}

Quantifiers may or may not do you the service. Read the javadoc for
java.util.regex.Pattern class.

I'm already using Pattern (albeit indirectly) for the String.matches'
regexp and I don't think there is a syntax to check the "dynamic" length.

 

[-]

/If/ it was possible to use regexp to check whether a string has a
total
length of x characters ; what API would you expect in regexp for this
purpose?

If you expect that method to be in String then String.length is that
method
If you expect that method to be in Pattern or in Matcher, I would argue
that it does not belong there.

It is possible to use regexp to check whether a string has a total of x
characters but my question pertains to a string which contains several
tokens and that each token can be of varying length.

A simple example would be:

[A] B [C]

where [A] and [C] are optional tokens and A, B, and C are strings of
varying length.

I can have several forms:

aa bbb
aaa b ccc
bbbbbb c
aaaaaaaa bbbbbbbbbb ccccccccc

so on and so forth.

What if I only want the total length to be less than x? Is there a
regexp construct that does that?

 

[Hemal Pandya]

What if I only want the total length to be less than x? Is there a
regexp construct that does that?

Not that I know of.

 

[Matthias Buelow]

What if I only want the total length to be less than x? Is there a
regexp construct that does that?

If you want to check for a string of length <= n, you have to check
for n optional characters. Either you write it out, or you use a
bound, if your regexp implementation allows that (see docs). But what
do you want to achieve with that? Surely checking for string length is
a lot faster than having the regex engine construct a finite automaton
from the expression and traverse that (which is what most regex
packages do, in some way or other.)

mkb.