使用“ for循环”添加数组值时发生异常

Question

I have some code here

 String array[]=new String[5];
    for(int i=0;i<array.length;i++){
        array[i]= "item "+String.valueOf(i);
        i++;
    }

and this is log message what i got after application crash

java.lang.IndexOutOfBoundsException : Invalid array range: 5 to 5

Could you guys explain me why pls ? I just want to declare an array and use for loop to initialize array element, just dont know why my code didn't work . Thank you

Answer 1

because key index More increases than index array in your loop .

String array[]=new String[5];
    for(int i=0;i<array.length;i++){
        array[i]= "item "+String.valueOf(i);

    }

Answer 2

remove extra i++.. it already redundant except you have some purpose to do so.

String array[]=new String[5];
for(int i=0;i<array.length;i++){
        array[i]= "item "+String.valueOf(i);
        //i++; //remove this.. it already redundant except you have some purpose
}

its java.lang.IndexOutOfBoundsException : Invalid array range: 5 to 5 because of the counter already exceed size of your string which 5 only..

use ArrayList instead

Answer 3

Just do this:

String array[]=new String[5];
for(int i=0;i<array.length;i++){
    array[i]= "item "+String.valueOf(i);
}

That second i++ was causing your index out of bounds.

Answer 4

Don't increment the 'i' value twice, which is causing this issue.

String array[]=new String[5];
for(int i=0;i<array.length;i++){
        array[i]= "item "+String.valueOf(i);
        //i++; //remove this..
}

Instead of using Array[] you can you Collections such as ArrayList<String> or List<String> .