1，Greedy 数量词
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X? X，一次或一次也没有 "[abc]?";
-
X* X，零次或多次 "[abc]*";
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X+ X，一次或多次 "[abc]+";
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X{n} X，恰好 n 次 "[abc]{5}";
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X{n,} X，至少 n 次 "[abc]{5,}";
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X{n,m} X，至少 n 次，但是不超过 m 次 "[abc]{5,15}”; 包含头。不包含尾
public class Demo4_Regex {
/**
* Greedy 数量词
X? X，一次或一次也没有
X* X，零次或多次
X+ X，一次或多次
X{n} X，恰好 n 次
X{n,} X，至少 n 次
X{n,m} X，至少 n 次，但是不超过 m 次
*/
public static void main(String[] args) {
//demo1();
//demo2();
//demo3();
//demo4();
//demo5();
String regex = "[abc]{5,15}";
System.out.println("abcba".matches(regex));
System.out.println("abcbaabcabbabab".matches(regex));
System.out.println("abcb".matches(regex));
System.out.println("abcbaabaabcbaaba".matches(regex));
}
public static void demo5() {
String regex = "[abc]{5,}";
System.out.println("abcba".matches(regex));
System.out.println("abcbaabcabbabab".matches(regex));
System.out.println("abcb".matches(regex));
System.out.println("abcbaaba".matches(regex));
}
public static void demo4() {
String regex = "[abc]{5}";
System.out.println("abcba".matches(regex));
System.out.println("abcbaabcabbabab".matches(regex));
System.out.println("abcb".matches(regex));
System.out.println("abcbaaba".matches(regex));
}
public static void demo3() {
String regex = "[abc]+";
System.out.println("".matches(regex));
System.out.println("a".matches(regex));
System.out.println("aaaaabbbbccccc".matches(regex));
}
public static void demo2() {
String regex = "[abc]*";
System.out.println("".matches(regex));
System.out.println("abc".matches(regex));
System.out.println("a".matches(regex));
}
public static void demo1() {
String regex = "[abc]?";
System.out.println("a".matches(regex));
System.out.println("b".matches(regex));
System.out.println("c".matches(regex));
System.out.println("d".matches(regex));
System.out.println("".matches(regex));
}
}