java - Galaxy S5 和 Android 5.1.1 上 do/while 语句的奇怪行为

Question

我在 Galaxy S5 和 Android 5.1.1 上遇到 do/while 语句的奇怪行为。如果您有任何信息，请告诉我。

int i = 0;
int j = 0;

do {
    Log.d(TAG, "[test do-while 1] i = " + i + ", j = " + j);
    i = 0;
    Log.d(TAG, "[test do-while 2] i = " + i + ", j = " + j);
    i++;
    Log.d(TAG, "[test do-while 3] i = " + i + ", j = " + j);
    i++;
    Log.d(TAG, "[test do-while 4] i = " + i + ", j = " + j);
    j++;
    Log.d(TAG, "[test do-while 5] i = " + i + ", j = " + j);
} while (j < 5);

如果我将程序运行在 Android 5.1.1 的 Galaxy S5 上，输出日志如下。

D/MainActivity( 9856): [test do-while 1] i = 2, j = 0
D/MainActivity( 9856): [test do-while 2] i = 2, j = 0
D/MainActivity( 9856): [test do-while 3] i = 2, j = 0
D/MainActivity( 9856): [test do-while 4] i = 2, j = 0
D/MainActivity( 9856): [test do-while 5] i = 2, j = 1
D/MainActivity( 9856): [test do-while 1] i = 2, j = 1
D/MainActivity( 9856): [test do-while 2] i = 2, j = 1
D/MainActivity( 9856): [test do-while 3] i = 2, j = 1
D/MainActivity( 9856): [test do-while 4] i = 2, j = 1
D/MainActivity( 9856): [test do-while 5] i = 2, j = 2
D/MainActivity( 9856): [test do-while 1] i = 2, j = 2
D/MainActivity( 9856): [test do-while 2] i = 2, j = 2
D/MainActivity( 9856): [test do-while 3] i = 2, j = 2
D/MainActivity( 9856): [test do-while 4] i = 2, j = 2
D/MainActivity( 9856): [test do-while 5] i = 2, j = 3
D/MainActivity( 9856): [test do-while 1] i = 2, j = 3
D/MainActivity( 9856): [test do-while 2] i = 2, j = 3
D/MainActivity( 9856): [test do-while 3] i = 2, j = 3
D/MainActivity( 9856): [test do-while 4] i = 2, j = 3
D/MainActivity( 9856): [test do-while 5] i = 2, j = 4
D/MainActivity( 9856): [test do-while 1] i = 2, j = 4
D/MainActivity( 9856): [test do-while 2] i = 2, j = 4
D/MainActivity( 9856): [test do-while 3] i = 2, j = 4
D/MainActivity( 9856): [test do-while 4] i = 2, j = 4
D/MainActivity( 9856): [test do-while 5] i = 2, j = 5

如果我将在其他设备或其他操作系统版本上运行相同的程序，输出如下。

D/MainActivity( 9515): [test do-while 1] i = 0, j = 0
D/MainActivity( 9515): [test do-while 2] i = 0, j = 0
D/MainActivity( 9515): [test do-while 3] i = 1, j = 0
D/MainActivity( 9515): [test do-while 4] i = 2, j = 0
D/MainActivity( 9515): [test do-while 5] i = 2, j = 1
D/MainActivity( 9515): [test do-while 1] i = 2, j = 1
D/MainActivity( 9515): [test do-while 2] i = 0, j = 1
D/MainActivity( 9515): [test do-while 3] i = 1, j = 1
D/MainActivity( 9515): [test do-while 4] i = 2, j = 1
D/MainActivity( 9515): [test do-while 5] i = 2, j = 2
D/MainActivity( 9515): [test do-while 1] i = 2, j = 2
D/MainActivity( 9515): [test do-while 2] i = 0, j = 2
D/MainActivity( 9515): [test do-while 3] i = 1, j = 2
D/MainActivity( 9515): [test do-while 4] i = 2, j = 2
D/MainActivity( 9515): [test do-while 5] i = 2, j = 3
D/MainActivity( 9515): [test do-while 1] i = 2, j = 3
D/MainActivity( 9515): [test do-while 2] i = 0, j = 3
D/MainActivity( 9515): [test do-while 3] i = 1, j = 3
D/MainActivity( 9515): [test do-while 4] i = 2, j = 3
D/MainActivity( 9515): [test do-while 5] i = 2, j = 4
D/MainActivity( 9515): [test do-while 1] i = 2, j = 4
D/MainActivity( 9515): [test do-while 2] i = 0, j = 4
D/MainActivity( 9515): [test do-while 3] i = 1, j = 4
D/MainActivity( 9515): [test do-while 4] i = 2, j = 4
D/MainActivity( 9515): [test do-while 5] i = 2, j = 5

• 如果我们将代码转换为 while 或 for 语句，则不会出现此问题。
• 如果我们使用同步文件 i/o 创建自己的日志库，就会出现问题。
• 不会出现在 Galaxy S4 和 S6 或 Android 5.0.2 上。

Answer 1

可能不是你要找的答案，只是作为测试(因为我很好奇):- 将 i 声明为 final，并为其分配 0 值。- 删除 i 的增量语句。

如果您得到相同的答案，那么:1. 你让我在其他地方声明为 2。2. 你发现了一个错误。

此外，如果您将 i 声明为 Integer 而不是 int，是否会出现此问题？这里有一些东西要学..