廖雪峰Java9正则表达式-1正则表达式入门-2正则表达式匹配规则

正则表达式的匹配规则：

• 从左到右按规则匹配

如何编写正则表达式

精确匹配

匹配规则及示例	可以匹配	不能匹配
"abc"	"abc"	不能匹配："ab", "Abc", "abcd"
特殊字符需要转义，如"a&c"，注意Java的字符串需要再加一个转义符	"a&c"	"ab", "abc", "a&cd"
非ascii字符用"\u####"表示一个unicode字符，如"a\u548cc"	"a和c"	"a与c","a&c","abc"
. 可以匹配任意一个字符："a.c"	"abc", "a&c"	"ac", "abbc"
\d 可以匹配一个数字："00\d"	"007", "008"	"00A", "0077"
\D可以匹配一个非数字："00\D"	"00A", "00#"	"001"
\w可以匹配一个字母、数字或下划线："java\w"	"javac", "java8", "java_",	"java#", "java "
\s可以匹配一个空白字符："A\sB"	"A B" "A B"，tab键也算空白字符	"AB" "A B"
\W可以匹配一个非字母、数字或下划线："java\W"	"java!", "java "	"javac", "java8", "java_"
\S可以匹配一个非空白字符："A\SB"	"A&B", "ABB"	"A B","A B"tab键也算空白字符
修饰符可以匹配前的任意个字符："A\d*"，先匹配字母A，再匹配任意多个数字	"A", "A1", "A007"	"AB"
修饰符+可以匹配+前的至少一个字符："A\d+"，先匹配字母A，再匹配至少1个数字	"A1","A007"	"A", "AB"
修饰符?可以匹配0个或1个字符："A\d?"，先匹配字母A，再匹配0个或1个数字	"A","A1"	"A12","AB"
修饰符{n}可以匹配n个字符："\d{6}"	"123456", "999999"	"12345","1234567", "12345A"
修饰符{m,n}，可以匹配m-n个字符"\d{3,5}"	"123", "12345"	"12","12345", "123A5"
修饰符{n,}可以匹配至少n个字符:"\d{3,}"	"123", "1234", "123456789"	"12","123A"

package com.testRegex;

public class Telephone {
    public static Boolean invaildTel(String s) {
        return s.matches("\\d{3,4}\\-\\d{6,8}");
    }
}

package com.testRegex;

import static org.junit.Assert.*;

import org.junit.Test;

public class TelephoneTest {

    @Test
    public void testInvaildTel() {
        assertTrue(Telephone.invaildTel("010-123456"));
        assertTrue(Telephone.invaildTel("010-12345678"));
        assertTrue(Telephone.invaildTel("0123-123456"));
        assertTrue(Telephone.invaildTel("0123-12345678"));
        assertTrue(Telephone.invaildTel("123-123456"));
        assertTrue(Telephone.invaildTel("123-12345678"));
        
        assertFalse(Telephone.invaildTel("010#123456"));
        assertFalse(Telephone.invaildTel("010X12345678"));
        assertFalse(Telephone.invaildTel("01-12345678"));
        assertFalse(Telephone.invaildTel("01234-12345678"));
        assertFalse(Telephone.invaildTel("01A-12345678"));
        assertFalse(Telephone.invaildTel("0123-12345"));
        assertFalse(Telephone.invaildTel("0123-12345X"));
        assertFalse(Telephone.invaildTel("0123-123456789"));
        assertFalse(Telephone.invaildTel("0123-12345678X"));
    }
}