QRegularExpression 是Qt 5.0才引进的,相对于QRegExp,QRegularExpression class修复了很多bug,提高了效率,提供了对Perl的RegEx几乎全面兼容的搜索引擎。简单说,QRegExp年久失修,bug较多,使用时建议使用QRegularExpression。
注意:若在正则表达式中需要用到”\”,需要在它前面补一个转义字符”\”,因为”\”在字符串中是一个转义字符会将后面的字符换算成ASCII码进行转义。所以如果要将”\”传递到正则当中就需要多添加一个”\”做转义。
- #include <QCoreApplication>
- #include <QDebug>
- #include <QRegExp>
- #include <QRegularExpression>
- #include <QRegularExpressionMatch>
-
- int main(int argc,char *argv[])
- {
- QString pattern1 = ".*=\\d*";
- QString pattern2 = "[a-z]*=\\d*";
- QString pattern3 = "\\w+";
- QString pattern4 = "(.+)=(.+)";
-
- QString test1("a=123");
- QString test2("-\r\na=123abc");
- QString test3("-_%\r\na=1abc-_%\r\na=12abc-_%\r\na=123abc-_%\r\na=1234abc");
- QString test4("hello world,hello qt");
-
- //test="a=123",pattern=".*=\\d*"
- QRegExp regExp(pattern1);
- qDebug()<<regExp.exactMatch(test1);//true
-
- //test="a=-\r\na=123abc",pattern="[a-z]*=\\d*"
- regExp.setPattern(pattern1);
- int pos = test2.indexOf(regExp);
- int matchedLen = regExp.matchedLength();
- QStringList capTexts = regExp.capturedTexts();
- qDebug()<<pos<<","<<matchedLen<<","<<capTexts;//0,8,("-\r\na-123")
-
- //test="-_%\r\na=1abc-_%\r\na=12abc-_%\r\na=123abc-_%\r\na=1234abc",pattern="[a-z]*=\\d*"
- regExp.setPattern(pattern2);
- //只会找到第一个就停止了
- pos = test3.indexOf(regExp);
- matchedLen = regExp.matchedLength();
- capTexts = regExp.capturedTexts();
- qDebug()<<pos<<","<<capTexts.length()<<","<<capTexts;//5,3,1,("a=1")
-
- //test="-_%\r\na=1abc-_%\r\na=12abc-_%\r\na=123abc-_%\r\na=1234abc",pattern="[a-z]*=\\d*"
- regExp.setPattern(pattern2);
- //替换所有,并返回该字符串的引用
- qDebug()<<test3.replace(regExp,"xyz");//-_%\r\nxyzabc-_%\r\nxyzabc-_%\r\nxyzabc-_%\r\nxyzabc"
- qDebug()<<test3;//-_%\r\nxyzabc-_%\r\nxyzabc-_%\r\nxyzabc-_%\r\nxyzabc"
-
- //////////////////////////////////////////////////////////////////////////////////////////////////////
-
- //test="hello world,hello qt",pattern="\\w+"
- //Since: Qt 5.0
- QRegularExpression regularExpression(pattern3);
- int index = 0;
- QRegularExpressionMatch match;
- do {
- match = regularExpression.match(test4,index);
- if(match.hasMatch()) {
- index = match.capturedEnd();
- qDebug()<<"("<<match.capturedStart()<<","<<index<<") "<<match.captured(0);
- //(0,5) "hello"
- //(6,11) "world"
- //(13,18) "hello"
- //(19,21) "qt"
- } else {
- break;
- }
- } while(index < test4.length());
-
- //test="a=-\r\na=123abc",pattern="\\w+"
- qDebug()<<test2.indexOf(regularExpression);//3
-
- //test="hello world,pattern="\\w+"
- qDebug()<<test4.replace(regularExpression,"x");//"x x,x x"
-
- //正则表达式分组
- //test="a=123",pattern="(.+)=(.+)"
- regularExpression.setPattern(pattern4);
- match = regularExpression.match(test1);
- qDebug()<<match.captured(0);//"a=123"
- qDebug()<<match.captured(1);//"a"
- qDebug()<<match.captured(2);//"123"
- qDebug()<<match.capturedTexts();//("a=100","a","100")
- return 0;
- }