Assigning values in an array using calculations involving each element's index

Question

My array has total 10 indices and I'm trying to set array[0] = 1/1, array[1] = 1/2, array[2] = 1/3, array[4] = 1/4 and so on.

After the calculation I want to display the elements with Sytem.out.println();

What am I doing wrong?

public static void main(String[] args) {
    final int VALUE =1;
    int[] array = new int[10];
    int counter=10;
    double result =0;
    for(int i =0; i<array.length; i++)
    {
        array[0]=VALUE/i;
        array[1]=VALUE/i;
        array[2]=VALUE/i;
        array[3]=VALUE/i;
        array[4]=VALUE/i;
        array[5]=VALUE/i;
        array[6]=VALUE/i;
        array[7]=VALUE/i;
        array[8]=VALUE/i;
        array[9]=VALUE/i;

    System.out.println( array[0] +" " + array[1] +" " + array[2] +" " + array[3]+" " +  array[4]+" "+array[5]+" " +array[6] +" " + array[7]+" " +   array[8]+" " +  array[9]+" " +  array[10]);
    }
}

What do you think array[0]=VALUE/i; does? What about array[1]=VALUE/i;, etc? What will they do differently each time through the loop? — azurefrog
– azurefrog, Commented Apr 18, 2016 at 16:23
i thought that, the i changes every single turn (i increasing by for loop +1) but it does not do that as i expect @azurefrog — Lena Monika Marshall
– Lena Monika Marshall, Commented Apr 18, 2016 at 16:57

nhouser9 · Accepted Answer · 2016-04-18 16:28:12Z

5

Two problems. The first is that your loop already takes care of going over each index in the array, so you can just do something like:

for (int i = 0; i < array.length; i++)
{
    array[i] = 1.0/(i+1);
    System.out.println(array[i] + " ");
}

The other is that you use an array of integers. By definition, an integer cannot be a fraction. Try using an array of doubles instead:

double[] array = new double[10];

answered Apr 18, 2016 at 16:28

nhouser9

6,7803 gold badges23 silver badges43 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Brandon Willis Over a year ago

Wasn't even thinking about how the OP defined the array. Good catch.

CubeJockey Over a year ago

@Brandon would be a good idea to update your answer with the same =)

Lena Monika Marshall Over a year ago

i've two questions. First of all thank you for your answer. I dont understand 2 thinks why didn't you use VALUE variabel. Second is does not i increase +1 already. If it is not why?

nhouser9 Over a year ago

@LenaMonikaMarshall I simply used 1.0 instead of the VALUE variable - that's basically the same thing since VALUE was set to 1 anyway. You could use VALUE if you wanted (just set it to a double instead of an int). As for your other question, I divide by (i + 1) because on the first iteration of your loop, i is 0. In that case, you don't want to get 1 divided by 0, you want to get 1 divided by one. So you need to use i + 1 instead of i.

Praveen Talavar · Accepted Answer · 2016-04-18 17:22:18Z

4

You are using a loop and also doing it inside manually. Just use the loops iterations to calculate it, and use the value of i for your array values.

for(int i = 0; i < array.length; i++)
{
    array[i] = VALUE/(i+1);
}

System.out.println( array[0] +" " + array[1] +" " + array[2] +" " + array[3]+" " +  array[4]+" "+array[5]+" " +array[6] +" " + array[7]+" " +   array[8]+" " +  array[9]);

Another problem, as mentioned by others, it that your result would be in fraction or floating point, and you are trying to store it in an int array

Use a float array instead

float[] array = new float[10];

edited Apr 18, 2016 at 17:22

answered Apr 18, 2016 at 16:23

Praveen Talavar

3231 silver badge11 bronze badges

7 Comments

Brandon Willis Over a year ago

Put parentheses around i+1 so it's VALUE/(i+1) and it'll be good to go.

Praveen Talavar Over a year ago

@BrandonWillis, Thanks. Done.

CubeJockey Over a year ago

Keep in mind storing the results of division using an integer.

Praveen Talavar Over a year ago

@CubeJockey, I wasn't updating as that was mentioned in other answer. Never mind, Updated. :)

Lena Monika Marshall Over a year ago

tthank you for reply @Pallavi. I write the code as you send and that's give eror. Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 10 at kapital11.kaptal11.main(kaptal11.java:14)

|

Collectives™ on Stack Overflow

Assigning values in an array using calculations involving each element's index

2 Answers 2

4 Comments

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related