关于正则数量词 - 黑马程序员技术交流社区

import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexDemo2 {
public static void main(String args[]) {
Demo2();
}
private static void getDemo() {
// TODO Auto-generated method stub
String str = "ming tian jiuyao fang jia le,da jia";
String reg = "\\b[a-z]{4}\\b";
Pattern p = Pattern.compile(reg);
Matcher m = p.matcher(str);
while (m.find()) {
System.out.println(m.group());
System.out.println(m.start() + "..." + m.end());
}
}
private static void Demo2() {
String str="008.109.090.030";
String reg="0+(\\d+)";//Greedy 数量词
Pattern p=Pattern.compile(reg);
Matcher m=p.matcher(str);
while( m.find() ){
System.out.print(m.group()+"--->");
int len= m.groupCount();
System.out.print(len+"-----");
for(int i=0;i<=1;i++){
System.out.print("group"+"("+i+"):"+m.group(i)+" ");
}
System.out.println(" ");
}
System.out.println("++++++++++++++++++++++++++++++++++++++");
String str1="008.109.090.030";
String reg1="0+(\\d+?)";//Reluctant 数量词
Pattern p1=Pattern.compile(reg1);
Matcher m1=p1.matcher(str1);
while( m1.find() ){
System.out.print(m1.group()+"--->");
int len= m1.groupCount();
System.out.print(len+"-----");
for(int i=0;i<=1;i++){
System.out.print("group"+"("+i+"):"+m1.group(i)+" ");
}
System.out.println(" ");
}
}
}
结果：
008--->1-----group(0):008 group(1):8
09--->1-----group(0):09 group(1):9
090--->1-----group(0):090 group(1):90
030--->1-----group(0):030 group(1):30
++++++++++++++++++++++++++++++++++++++
008--->1-----group(0):008 group(1):8
09--->1-----group(0):09 group(1):9
09--->1-----group(0):09 group(1):9
03--->1-----group(0):03 group(1):3

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