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));}}