D11117235catian

Java方法length(),cherAt,EXCEL public class Main { /**/ public static void main(String[] args) { String a = "狗吃屎,貓抓鼠,老猴愛作怪", b = ""; System.out.println("原來: " + a); int c = a.length();/*計算字串長度length()方法*/ System.out.println("長度: " + c); for (int i = 0; i

public class Main { /*黃柏諺recursion遞迴函數*/ public static void main(String[] args) { int x = 11; /*Java程式必須以main開始*/ for (int i = 0; i 0) { return k + sum(k - 1);} else {return 0;} } /*函數sum呼叫自己,稱遞迴*/ public static int f(int k) { if (k > 0) { return k * f(k - 1);} else {return 1;} } /* 0!=1, 7!=7*6!,......*/ }