正則表示式(數量詞)
阿新 • • 發佈:2018-11-06
public class Demo4_Regex { /** * Greedy 數量詞 X? X,一次或一次也沒有 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,但是不超過 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)); } }