Java基础知识

一、匹配

1public class RegularExpressionDemo{
2	public static void main(String[] args){
3		
4		//匹配电话号码
5		String telphoneNum= "0015012828944";
6		String reg= "^(13[0-9]|14[579]|15[0-3,5-9]|16[6]|17[0135678]|18[0-9]|19[89])\\d{8}$";
7		System.out.println(telphoneNum.matches(reg));
8		
9	}
10}

二、切割

1public class RegularExpressionDemo{
2	public static void main(String[] args){
3		
4		//把语句切割为单词
5		String sentence = "welcome  to  china ";
6		String reg = " +";
7		String[] words = sentence.split(reg);
8		for(String word : words){
9			System.out.println(word);
10		}
11	}
12}

三、替换

1public class RegularExpressionDemo{
2	public static void main(String[] args){
3		
4		//把字符串中的标点符号换成空
5		String sentence = "How are you? Fine, thanks.";
6		String reg = "[?,.]";
7		sentence = sentence.replaceAll(reg,"");
8		System.out.println(sentence);
9	}
10}

四、获取

1import java.util.regex.Pattern;
2import java.util.regex.Matcher;
3
4public class RegularExpressionDemo{
5	public static void main(String[] args){
6		
7		//获取句子中所有长度为3的单词
8		String sentence = "How old are you? I'm 27 years old. what about you? So am I.";
9		String reg = "[a-zA-Z]{3}";
10		
11		Pattern p = Pattern.compile(reg);
12		Matcher m = p.matcher(sentence);
13		
14		while(m.find()){
15			System.out.println(m.group());
16		}
17	}
18}