1.使用正则表达式分割字符串：
String[] string.split(String regex);
"a b c".split("\s");->[a, b, c]
"a b c".split("\s");->[a, b, , , , c]
"a b c".split("\s+");->[a, b, c]
"a,b:;c".split("[\,\:\;\s]+");->[a, b, c]
public static void main(String[] args){
String tags = "java php python";
String[] arr = tags.split("\s");
System.out.println(Arrays.toString(arr));
}
```#java
public class SplitString {
public static void main(String[] args){
String tags = "java php python";
String[] arr = tags.split("\s+");
System.out.println(Arrays.toString(arr));
}
}
```
```#java
public class SplitString {
public static void main(String[] args){
String tags = "java, php;: python";
String[] arr = tags.split("[\,\;\:\s]+");
System.out.println(Arrays.toString(arr));
}
}
```
2.使用正则表达式查找字符串
package com.testList;
import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class SearchString {
public static void main(String[] args){
String s = "The quick brown fox jumps over the lazy dog.";
//区分大小写
Pattern p1 = Pattern.compile("the");
Matcher m1 = p1.matcher(s);
while(m1.find()){
String sub = s.substring(m1.start(),m1.end());
System.out.print(sub+",start="+m1.start()+" end="+m1.end()+" ");
}
System.out.println();
//不区分大小写
Pattern p2 = Pattern.compile("the",Pattern.CASE_INSENSITIVE);
Matcher m2 = p2.matcher(s);
while(m2.find()){
String sub = s.substring(m2.start(),m2.end());
System.out.print(sub+",start="+m2.start()+" end="+m2.end()+" ");
}
System.out.println();
//匹配每个单词
Pattern p3 = Pattern.compile("\w+",Pattern.CASE_INSENSITIVE);
Matcher m3 = p3.matcher(s);
while(m3.find()){
String sub = s.substring(m3.start(),m3.end());
System.out.print(sub+",start="+m3.start()+" end="+m3.end()+" ");
}
System.out.println();
//匹配带有o的单词
Pattern p4 = Pattern.compile("\w*o\w*",Pattern.CASE_INSENSITIVE);
Matcher m4 = p4.matcher(s);
while(m4.find()){
String sub = s.substring(m4.start(),m4.end());
System.out.print(sub+",start="+m4.start()+" end="+m4.end()+" ");
}
}
}
3.使用正则表达式替换字符串
public class SplitString {
public static void main(String[] args){
String s = "The quick brown fox jumps over the lazy dog.";
//区分大小写
String r = s.replaceAll("\s+"," ");//参数依次为正则表达式，用于替换的字符
System.out.println(r);
String r2 = s.replaceAll("(\w+)","<b>$1</b>");//$1方向引用，指向前面捕获的单词
System.out.println(r2);
}
}
4.总结
使用正则表达式可以：
- 分割字符串：String .split()
- 搜索字串：Matcher.find()
- 替换字符串：String.replaceAll()