补充下以前用的比较少的三元运算符, 其它也没什么说的了..
三元运算符
expression1 ? expression2 : expression3
等同于:
if (expression1) { expression2; } else { expression3; }
流程控制的例子
判断季度
class QuarterDemo1 { public static void main(String[] args) { int nMonth = 5; switch (nMonth) { case 1: case 2: case 3: System.out.println("First Quarter"); break; case 4: case 5: case 6: System.out.println("Second Quarter"); break; case 7: case 8: case 9: System.out.println("Third Quarter"); break; case 10: case 11: case 12: System.out.println("Fourth Quarter"); break; } } } class QuarterDemo2 { public static void main(String[] args) { int nMonth = 3; int nQuarter = (nMonth - 1) / 3 + 1; System.out.println(nQuarter + " " + "Quarter"); } }
9 * 9 乘法表
class MultiplyDemo { public static void main(String[] args) { for (int i = 1; i <= 9; i++) { for (int j = 1; j <= i; j++) { // 下面两种方式都是用来对齐打印的 System.out.print(i + "*" + j + "=" + (i * j) + '\t'); System.out.printf("%d * %d = %-5d", i, j, (i * j)); } } } }
对齐打印, 可以用 ‘\t’ 制表符, 或者使用 ‘%-5d’ 来格式化.
-5表示输出 5 个光标位, 如下图:
☠