Java Regular Expressions 4 common functions

Regular regular expressions have a powerful function in string processing, and sun has added support for it in jdk1.4

Here's a simple list of 4 common features:

Inquire:

String str= "ABC efg ABC";

String regex= "A|f"; Represents a or F

Pattern P=pattern.compile (regEx);

Matcher M=p.matcher (str);

Boolean rs=m.find ();

If there is a regex in Str, then RS is true, otherwise it is flase. If you want to ignore case when looking, you can write pattern p=pattern.compile (regex,pattern.case_insensitive);

Extraction:
String regex= ". +\\\\ (. +) $";

String str= "C:\\dir1\\dir2\\name.txt";

Pattern P=pattern.compile (regEx);

Matcher M=p.matcher (str);

Boolean rs=m.find ();

for (int i=1;i<=m.groupcount (); i++) {

System.out.println (M.group (i));

}

The above results are name.txt, and the extracted strings are stored in m.group (i), where I maximum is m.groupcount ();

Segmentation:

String regex= "::";

Pattern P=pattern.compile (regEx);

String[] R=p.split ("XD::ABC::CDE");

After execution, R is {"XD", "abc", "CDE"}, in fact, there are simple ways to split:

String str= "XD::ABC::CDE";

String[] R=str.split ("::");

Replace (delete):

String regex= "A +"; Represents one or more a

Pattern P=pattern.compile (regEx);

Matcher M=p.matcher ("aaabbced a Ccdeaa");

String S=m.replaceall ("A");

The result is "abbced A Ccdea"

If you write an empty string, you can achieve the deletion function, for example:

String S=m.replaceall ("");

The result is "bbced ccde"

Report:

\d equal to [0-9] numbers
\d is equal to [^0-9] not digital
\s is equal to [\t\n\x0b\f\r] blank character
\s is equal to [^ \t\n\x0b\f\r] non-blank character
\w is equal to [a-za-z_0-9] numbers or English characters.
\w is equal to [^a-za-z_0-9] non-numerals and English characters

^ represents the beginning of each line
$ indicates the end of each line