Chapter 5 Java switch case switchexpression case expression

Chapter 5 Java語法(二)

switch case 判斷敘述 switch(expression) { case expression: statements; break; . . . default: (可省略) statements; break; }

switch case 判斷敘述 l Example <% char sex=‘M’; switch(sex) { case ‘M’: out. println(“男生”); break; case ‘F’: out. println(“女生”); break; default: out. println(“性別未知”); break; } %>

while 迴圈 while(條件式) { statements; . . . }

while 迴圈 Example <% int i=1; int sum=0; while(i<=99) { sum = sum + i; i += 2; } out. println(sum); %> l

do. . . while迴圈 do { statements; . . . } while (條件式);

break 與 continue int sum=0; for(int i=1; i<=200; i+=2) { if (i==101) break; sum+=i; } out. println(sum); 終止整個迴圈

break 與 continue int sum=0; for (int i=1; i<=99; i++) 終止某次迴圈的執行 { if (i%2==0) continue; sum += i; } out. println(sum);

Example int. Ary[]; int. Ary = new int[5]; or int. Ary[] = new int[5]; int. Ary[0] int. Ary[1] int. Ary[2] int. Ary[3] int. Ary[4]

陣列元素的存取 int. Ary[] = new int[10]; for(int i=0; i<10; i++) { int. Ary[i] = i * 10; } int. Ary[4] = 10; or int. Ary[] = {10, 20, 30, 40 };

二維與多維陣列 int. Ary[][] = new int[3][4] int. Ary[0][0] int. Ary[1][0] int. Ary[2][0] int. Ary[0][1] int. Ary[1][1] int. Ary[2][1] int. Ary[0][2] int. Ary[1][2] int. Ary[2][2] int. Ary[0][3] int. Ary[1][3] int. Ary[2][3] int. Ary[][][]. . . = new int[2][3][4]. . .

陣列長度的取得 int j, k; int. Ary 1[] = new int[6]; int. Ary 2[][] = new int[3][5]; j = int. Ary 1. length; k = int. Ary 2[0]. length; 陣列變數. length