CODEWITHSUNDEEP
javaarrayssorting
Lauren McCabe
Lauren McCabe

Reputation: 117

Java program sort random array

So the purpose of this program is to selectively sort a random array of integers form largest to smallest. To do this, I needed to keep swapping the first element with the largest element. I think my methods are correct, but I am fairly new to Java and not sure what to call in main in order to execute my methods correctly. Thank you in advance!

 package sortarray;

 public class SortArray {

 public static int randomInt(int low, int high) { 
double e;
double x=Math.random();
e=low+x*(high-low);
return (int)e;
}
public static int[] randomIntArray(int n) { 
int[] a = new int[n];
for(int i = 0; i < a.length; i++) {
    a[i] = randomInt(-5, 15);
}
return a;
}

public static int indexOfMaxInRange(int[] a, int low, int high) {
int index = low;
for (int i = low + 1; i < a.length; i++) {
    if (a[i] > a[index]) {
        index = i;
    }
}
return index;
}

public static void swapElement(int[] a, int index1, int index2) {
    int temp = a[index1];
    a[index1] = a[index2];
    a[index2] = temp; 
}

public static void sort(int[] a) {
    int length = a.length;
    //use length-1 because do not need to swap last element with itself
    for (int i = 0; i < length-1; i++) {
        int indexOfMax = indexOfMaxInRange(a, i, length-1);
        swapElement(a, i, indexOfMax); 
    }
}

public static void printArray(int[] a) {
for(int i = 0; i < a.length; i++) {
    System.out.print(" " + a[i]);
}
}


public static void main(String[] args) {
 int[] array = randomIntArray(30);
    printArray();     
}

}

Upvotes: 3

Views: 1463

Answers (5)

Adam
Adam

Reputation: 846

Here is my code that I posted on Code Review. This sort an array of String, But you can put integer instead. https://codereview.stackexchange.com/questions/160243/sort-a-given-string-in-ascending-order

Given string

[H, B, D, G, F, E, A, C]

Output

[A, B, C, D, E, F, G, H]

public class sortArray {
    public static void sort (String[] str)
    {
        int lastPos = str.length - 1;
        int minPos = 0;
        String s = "";
        for (int i = 0; i < lastPos; i++)
        {
            minPos = i;
            for (int j = i + 1; j <= lastPos; j++)
                if (str[j].compareTo (str[minPos]) < 0)
                    minPos = j;
            if (minPos != i)
            {
                s = str[i];
                str[i] = str[minPos];
                str[minPos] = s;
            }
        }
    }

    public static void main(String[] args){
        String[] str = {"H", "B", "D", "G","F", "E", "A", "C"};
        sort(str);
        System.out.println(Arrays.toString(str));
    }
}

Upvotes: 2

Rajesh Chaudhary
Rajesh Chaudhary

Reputation: 112

you can use inbuilt function of Arrays. Simply call the inbuilt method and pass your array.

Arrays.sort(pass your array here).

If you dot want to use inbuilt method please refer this link.

Java : Sort integer array without using Arrays.sort()

Upvotes: 1

Lee
Lee

Reputation: 27

There must have the arguments in the methods you use, you should put the array in the ( )

Upvotes: 1

JUAN CALVOPINA M
JUAN CALVOPINA M

Reputation: 3955

Also you can call the method sort() within of printArray() method, so when you call printArray() it will print sorted:

...
public static void printArray(int[] a) {
    sort(a);
    for (int i = 0; i < a.length; i++) {
        System.out.print(" " + a[i]);
    }
}


public static void main(String[] args) {
    int[] array = randomIntArray(30);
    printArray(array);
}
...

Upvotes: 2

Jacob G.
Jacob G.

Reputation: 29680

To sort the array, you simply need to call the following:

sort(array);

Then, you can print the array again to verify that it is sorted with:

printArray(array);

Upvotes: 2

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