java - Add a number to "Number[]" in a loop

Question

Its a pretty simple question, how do i add a number to "Number[]" one at a time?

Its a simplified example: normally to fill number we do this:

Number[] series1Numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9}

But how do i add a number to the end of this? like this should result in the same as above:

for(int i=1; i<10; i++){
nextNumber = i;

Number[] seriesOfNumbers = {+ nextNumber}; //This dosnt work, so i need to change it somehow
}

score 3 · Accepted Answer

如果您已经知道尺寸，那很容易：

Number[] seriesOfNumbers = new Number[9];
for(int i=1; i<10; i++){
    nextNumber = i;
    seriesOfNumbers[i - 1] = nextNumber;
}

但是，通常最好使用 a List：

List<Number> seriesOfNumbers = new ArrayList<Number>();
for(int i=1; i<10; i++){
    nextNumber = i;
    seriesOfNumbers.add(nextNumber);
}

数组总是有一个固定的大小——一旦你创建了数组对象，你就不能添加或删除元素；你只能设置和获取它们。ArrayList<T>仍然使用数组作为后备存储，但在需要时创建一个新数组（并复制现有值）以容纳更多项目。

score 1 · Accepted Answer

另一种解决方案可能是：

Number[] seriesOfNumbers = new Number[9];

for(int i=0; i<seriesOfNumbers.length; i++)
{
    seriesOfNumbers[i] = i+1;

}

score 1 · Accepted Answer

使用 aCollection而不是数组：

List<Number> series1Numbers = new ArrayList<Number>

 for(int i=1; i<10; i++)
  series1Numbers.add(i);

如果你需要数组

Number []series1NumbersArray = new Number[series1Numbers.size()];
series1Numbers.toArray(series1NumbersArray);

3 回答 3