How to store output looped elements of an array in another array

Question

I have edited a java method for finding peaks by comparing its neighboring elements. But I have a problem in storing the values in the output array...

Here is the method that is edited, commented is my problem

public static int[] peakInArray(int[] arr2){
    int i;
    int lenghtInput = arr2.length;
    int[] peaks = new int[lenghtInput];
    for (i = 1; i<arr2.length - 1; i++) {
        if (arr2[i] > arr2[i - 1] && arr2[i] > arr2[i + 1]);
       // PROBLEM: store arr2[i] in peaks
        peaks[i] = arr2[i];
    }
    return peaks;
}

Is there a compilation/runtime error? If so, please paste it. Is something else going wrong? Telling us you have a "problem" is really vague. — Ironcache
– Ironcache, Commented May 5, 2016 at 17:04
if the condition is satisfy you want to store that value in another array right still you are using same index i for peaks !! — Rachit Solanki
– Rachit Solanki, Commented May 5, 2016 at 17:08
The problem is that you've used if(...); the ; at the end makes this if statement useless. — Titus
– Titus, Commented May 5, 2016 at 17:08
OP, if your issue is that peaks is storing everything from arr2, then what @Titus eluded to (replace ; with {}, like your for loop) is likely the solution. If you notice other problems, please post more detailed info about what the actual problem is. — Ironcache
– Ironcache, Commented May 5, 2016 at 17:20

Sammy T · Accepted Answer · 2016-05-05 19:51:28Z

1

Like everyone already said, your if statement shouldn't be working the way you have it. It needs to be:

if(yourComparison){
   peaks[i] = arr2[i];
}

Also, if you want your result to only be as big as it needs to be, you need to use an ArrayList. There's an example at the bottom of this page:

http://www.tutorialspoint.com/java/java_arraylist_class.htm

answered May 5, 2016 at 19:51

Sammy T

1,9341 gold badge15 silver badges21 bronze badges

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

Comments

Jerico Manalastas · Accepted Answer · 2016-05-06 04:08:41Z

0

To all who helped me in my problem, thanks! I've figured it out with your help and with some researches.

Here is the final method...

public static int[] peakInArray(int[] arr2){

    int lengthInput = arr2.length;
    int[] peaks = new int[lengthInput];
    int peakIndex = 0;

    for (int i = 1; i<lengthInput - 1; i ++) {
        if (arr2[i] > arr2[i - 1] && arr2[i] > arr2[i + 1]) {
            //Store arr2[i] in peaks
            peaks[peakIndex] = arr2[i];
            peakIndex++;
        }
    }
 return peaks;
}

answered May 6, 2016 at 4:08

Jerico Manalastas

551 silver badge9 bronze badges

Collectives™ on Stack Overflow

How to store output looped elements of an array in another array

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related