[SOLVED]QRegExp allow only one white space between strings

[jpincz]

Hi, guys maybe you can help with this i really tried but it is very difficult to undertand
i read from here :https://qt-project.org/doc/qt-4.8/qregexp.html
if you have a more comprehensive link would be grateful.

A definition for this example W == any string that does not contain a white space.

I'm trying to write the following regular expression

W[space] - - - - - - not allowed (match==false)

[space]W - - - - - - not allowed (match==false)

W[space]W - - - - - ALLOWED (match==true)

W[space][space]W - - - not allowed (match==false)

W[space]W [space]W - - - ALLOWED (match==true)

W[space]W [space][space]W - - - not allowed (match==false)

W[space]W [space]W[space] - - - not allowed (match==false)

[space]W[space]W [space]W - - - not allowed (match==false)
so on........
.............

SOLUTION:
QRegExp rx("^\S+(\s\S+)+$");

still macth this case WORD[SPACE] but works for me , thanks to ChrisW67

usefull link:
"RegExp example...":http://qt-project.org/doc/qt-4.8/tools-regexp.html

[SGaist]

Hi and welcome to devnet,

Can you provide a concrete string and QRegExp code example ?

[jpincz]

first sorry for my english and thanks for you reply..
i read this documentation:

https://qt-project.org/doc/qt-4.8/qregexp.html

and it si very hard to undertand still i tried , dont put code as example bcz dont want someone answer base on them

if u have another link with differents or more examples i will be gratefull

the more closer i get was with this:

("^\s*\w+(\s?$| {2,}\w+)+");

i found taht code here (javascript)

http://stackoverflow.com/questions/16756507/regexp-which-allow-only-one-space-in-between-words

but what i need have to match with strings made of word characters and NONword characters(obv excluiding " ") and can have only one space between them but not a first or last as i detailed in my first post

example of a match:

@QString s="lucas" + " " + "tornado" + " " + "n°1995" + " " + "12-12-12" + " " + "erkntowertn";@

examples of a non match:

@QString s= "lucas" + " ";
QString s= " " + "lucas";
QString s= "lucas" + " " + " " + "tornado";@

i am gonna use it as this on qline edit:

@ QRegExp rx("MAGIC");
ui->lineEditDesc->setValidator(new QRegExpValidator(rx, ui->lineEditDesc));@

for now i use this

@void NewProduct::on_lineEditDesc_textEdited(const QString &arg1)
{
ui-> lineEditDesc-> setText(arg1.simplified());
}@

but i that way the user can not put a space on the end of the word to start another word , he has to write all together and then put the spaces

[ChrisW67]

I would think something like:
@
QRegExp rx("^\S+(\s\S+)+$"); // if there must be two or more words
QRegExp rx("^\S+(\s\S+)*$"); // if only one word will do
@
would match lines starting and ending with a "word" and containing only single spaces and words in between.

[koahnig]

You might find the "RegExp example":http://qt-project.org/doc/qt-4.8/tools-regexp.html quite useful for trial and error with different expressions.