我的两个变量无法解析为变量

Question

public static void nextGeneration(boolean[][] currentWorld, boolean[][] newWorld) {

    boolean[][] world = null;
    world = currentWorld;
    int numLivingNeighbors = 0;
    for (int i = 0; i < currentWorld.length; i++)
        for (int j = 0; j < currentWorld[i].length; j++)
            numLivingNeighbors =numNeighborsAlive(world, i, j);
            boolean cellCurrentlyLiving = world[i][j];
            isCellLivingInNextGeneration(numLivingNeighbors,currentWorld[i[j]);

我收到一条错误消息，说i和j无法解析为变量。 我尝试声明它们，但后来我得到一个错误，声明它们已被声明两次。

Answer 1

您需要在for循环中使用括号：

public static void nextGeneration(boolean[][] currentWorld, boolean[][] newWorld) {
    boolean[][] world = null;
    world = currentWorld;
    int numLivingNeighbors = 0;
    for (int i = 0; i < currentWorld.length; i++) {
        for (int j = 0; j < currentWorld[i].length; j++) {
            numLivingNeighbors =numNeighborsAlive(world, i, j);
            boolean cellCurrentlyLiving = world[i][j];
            isCellLivingInNextGeneration(numLivingNeighbors,currentWorld[i[j]);
        }
    }

    // might there be other code you did not show us?

    return;
}

当你使用for循环而没有括号时，它只会将直线或后续行视为循环的一部分。因此，您的原始代码实际上与此相同：

for (int i = 0; i < currentWorld.length; i++) {
    for (int j = 0; j < currentWorld[i].length; j++) {
        numLivingNeighbors =numNeighborsAlive(world, i, j);
    }
}
boolean cellCurrentlyLiving = world[i][j];
isCellLivingInNextGeneration(numLivingNeighbors,currentWorld[i[j]);

换句话说，您引用了实际循环的loop变量i和j 。