[英]How to add thing by specific index in arraylist in java without raise IndexOutOfBoundsException?
the code: 编码:
import java.util.*;
import java.lang.*;
import java.io.*;
class Ideone
{
public static void main (String[] args) throws java.lang.Exception
{
ArrayList<String> temp = new ArrayList<String>();
temp.add(0,"123");
temp.add(3,"123");
}
}
result: 结果:
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 3, Size: 1
I know I can just use .add("String")
to add anything I want in arraylist without caring about index. 我知道我可以只使用
.add("String")
在arraylist中添加我想要的任何内容,而无需关心索引。 However, what I want is to add "String"
in specific index. 但是,我想要在特定索引中添加
"String"
。 Is there any way to do so without raising IndexOutOfBoundsException? 有什么办法可以在不引发IndexOutOfBoundsException的情况下进行操作?
You can check if the index where you want the new String to be is OutOfBounds or not, for example: 您可以检查希望新String所在的索引是否为OutOfBounds,例如:
ArrayList<String> temp = new ArrayList<String>();
temp.add(0,"123");
int index = 3;
if (temp.size() > index){
temp.add(index,"123");
}
When it is OutOfBounds you can create a larger ArrayList or add it to a lower indexNumber. 当它是OutOfBounds时,您可以创建一个较大的ArrayList或将其添加到较低的indexNumber。
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