Question

我正在使用2个数组，一个是arrayWeight，另一个是arrayId。它们都通过List接收数据库中的值。

List<oldDetails> details = olddb.getDetails();
        for (oldDetails cn : details) { //Adding weights and id of all time to an array.
            double num = cn.getWeight();
            int id = cn.getId();
            Log.d("num", "equals: " + num);
            for (int i = 0; i < count; i++) {
                arrayWeight[i] = num;
                arrayId[i] = id;
            }
        }
Log.d("Array", "equals: " + Arrays.toString(arrayWeight));

在LogCat之后，for循环的每一步都是我收到的：

D/num: equals: 70.6
D/num: equals: 60.7
D/num: equals: 8000.0
D/num: equals: 80.6
D/Array: equals: [80.6, 80.6, 80.6, 80.6]

现在我愿意在我的阵列中实现这个目标：

D/num: equals: 70.6
D/num: equals: 60.7
D/num: equals: 8000.0
D/num: equals: 80.6
D/Array: equals: [70.6, 60.6, 8000.0, 80.6]

如何解决数组中只接收列表中的一个值的问题，而不是全部问题？

Answer 1

您的内部循环将每个值从detail复制到数组arrayWeigth和arrayId中的每个值，因此在最后一次迭代中它会替换每个值。使用单个常规for循环而不是嵌套循环。像，

for (int i = 0; i < details.size(); i++) {
    OldDetails cn = details.get(i);
    double num = cn.getWeight();
    int id = cn.getId();
    Log.d("num", "equals: " + num);
    arrayWeight[i] = num;
    arrayId[i] = id; 
}

或更短，

for (int i = 0; i < details.size(); i++) {
    OldDetails cn = details.get(i);
    arrayWeight[i] = cn.getWeight();
    arrayId[i] = cn.getId();
    Log.d("num", "equals: " + arrayWeight[i]);
}

Array继续向列表循环中的所有索引添加相同的值

1 个答案: