flip the array

Question

Why is not the inverted array displayed? that is, the last element of the array should be the first, and so on.

public class Mane { public void sort(int[] massive){ int[]arraySort = new int[10]; for(int i = 4; i >= 0; i--){ arraySort[4 - i] = massive[i]; for(int a = 0; a < 5; a++){ massive[a] = arraySort[a]; } } } public static void main(String[] arg){ int[] mass = {1,2,3,4,5}; Mane m = new Mane(); m.sort(mass); for(int i: mass){ System.out.println(i); } } }

I'm certainly not an expert, but even the code is too messy.

Raider Raider 805 four 6 · Accepted Answer · 2016-02-08T16:43:30

Why two arrays, why nested loops?

 public void sort(int[] massive) { for (int i = 0; i < massive.length / 2; i++) { int tmp = massive[i]; massive[i] = massive[massive.length - i - 1]; massive[massive.length - i - 1] = tmp; } }

I do not know why, but I have java.lang.ArithmeticException: divide by zero

Community spirit ♦ one · Answer 2 · 2016-02-08T16:47:45

 Collections.reverse(Arrays.asList(source)).toArray(new int[source.length]);

yes, it will use redundant resources; no it's not scary

https://stackoverflow.com/a/22828623/2908793

Community spirit ♦

one

etki

33.2k 2 45 71

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Justify the phrase "no, it's not scary." Are you by any chance a Google Chrome developer? - Raider
Cool, but it won't work on primitives, java.util.Collections.reverse returns nothing, toArray(new int[whatever]) will not work either. ZIS FROM JAVA! 11 - zRrr
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In addition, Arrays.asList creates a view above the array, and the set calls on this list change the source array, i.e. for Integer[] source = {1, 2, 3, 4, 5}; calling Collections.reverse(Arrays.asList(source)) will rearrange the source . - zRrr
@zRrr yes, I fell for it , the answer was written in parallel while talking in the office, shame on me. - etki
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The end user doesn’t care how much time is spent on the code - the main thing is for it to work and work quickly. Your code: 1) does not work, 2) even if corrected, it creates an unnecessary copy of the array in memory. If you teach a beginner, then why just bad? - Raider

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Sergey Sergey 61 one 2 7 · Answer 3 · 2016-02-08T16:53:40

Thank you all for your help, I figured it out

 public class Mane { public void sort(int[] massive){ int[]arraySort = new int[5]; for(int i = 4; i >= 0; i--){ arraySort[4 - i] = massive[i]; } for(int a = 0; a < 5; a++){ massive[a] = arraySort[a]; } } public static void main(String[] arg){ int[] mass = {1,2,3,4,5}; Mane m = new Mane(); m.sort(mass); for(int i: mass){ System.out.println(i); } } }

everyone liked it, but for some reason it didn’t work as it should
It does not create a copy of the array, and does not depend on its length.

Andrey Kremenets Andrey Kremenets one · Answer 4 · 2019-06-04T19:18:20

 for(int i = 0; i < array.length; i++) array[i] =(-1)*array[i]; Arrays.sort(array); for(int i = 0; i < array.length; i++) array[i] =(-1)*array[i];

flip the array

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