primitive problem with arrays.

Creamy Goodness

three threads in as many weeks, i think i've lost my programming skills .

i have two arrays

private int[] array_of_five = new int[5]; // stores 5 random int values.

private int[] array_of_seven = new int[6];

the array_of_five can only store numbers between 1 and 6.
the array_of_six is set up to count how many 1's, 2's ... 6's. there are in the array_of_five.

so i have a simple function like this

public void function(){
       for(int i = 0 ; i < array_of_six.length ; i++)
                 array_of_six[i] = 0 ;
       
       java.util.Arrays.sort(array_of_five);

       for(int i = 0 ; i < array_of_six.length ; i++)
                     array_of_six[ array_of_five[i] ]++;
       }
}

basically if array of five is sorted and looks like this {1,1,3,4,6} i want array_of_six to look like this {2,0,1,1,0,1} eg (two 1's) (no 2's) (one 3) (one 4) (no 5's) (one 6).

i'm getting an Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 5 and it points me to the line in the above code that is

array_of_six[ array_of_five[i] ]++;

am i going about filling array_of_six the wrong way totally?

Webmonkey

Well you are going out of bounds because array_of_five can only index from 0 - 4 and array_of_six goes from 0 - 5. Now in the last for loop you are using i to go from 0 - 5, but using i in the array_of_five so you will end up trying to access array_of_five[5] when it only goes up to index 4 since it is 5 in length.

AlmightyCushion

array_of_five only has five elements in it but you do the loop 6 times. On the sixth iteration of the loop you say array_of_five. i will be equal to 5 at this stage so you are trying to access the sixth element in array_of_five which doesn't exist.

Cantab.

Cremo wrote: »

three threads in as many weeks, i think i've lost my programming skills .

i have two arrays

private int[] array_of_five = new int[5]; // stores 5 random int values.

private int[] array_of_seven = new int[6];

the array_of_five can only store numbers between 1 and 6.
the array_of_six is set up to count how many 1's, 2's ... 6's. there are in the array_of_five.

so i have a simple function like this

public void function(){
       for(int i = 0 ; i < array_of_six.length ; i++)
                 array_of_six[i] = 0 ;
       
       java.util.Arrays.sort(array_of_five);

       for(int i = 0 ; i < array_of_six.length ; i++)
                     array_of_six[ array_of_five[i] ]++;
       }
}

basically if array of five is sorted and looks like this {1,1,3,4,6} i want array_of_six to look like this {2,0,1,1,0,1} eg (two 1's) (no 2's) (one 3) (one 4) (no 5's) (one 6).

i'm getting an Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 5 and it points me to the line in the above code that is

array_of_six[ array_of_five[i] ]++;

am i going about filling array_of_six the wrong way totally?

What about that loose curly brace?

Creamy Goodness

lol, the second i posted this up i reread the post and noticed my mistake.

the second for loop should of read.

for(int i = 0 ; i < array_of_five.length ; i++)
                     array_of_six[ array_of_five[i] ]++;

case closed

that stray curly brace was a typo

thanks for the help guys, it's mucho appreciatedo

Webmonkey