//已知循环次数用for循环；不知道循环次数用while. //break跳出当前循环 //continue返回判断条件 //while示例 public class Test{ public static void main(String[] args){ int a=100; int b=4; while(a>b){ System.out.println(a); a–; } } } //构建树 public class Test1{ public static void main(String[] args){ int line=5; for(int i=1;i<line;i++){ for(int j=1;j<=line-i;j++){ System.out.print(" “); } for(int j=1;j<=i;j++){ System.out.print(”* “); } System.out.println(); } for(int i=1;i<=2;i++){ for(int j=1;j<line-1;j++){ System.out.print(” “); } for(int j=1;j<=2;j++){ System.out.print(”| “); } System.out.println(); } } } //乘法口诀表 public class Test2{ public static void main(String[] args){ for(int i=1;i<=9;i++){ for(int j=1;j<=i;j++){ System.out.print(i+”"+j+"="+ij+"\t"); } System.out.println(); } } }
