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Ruby program to sort an array in ascending order using quick sort

Last Updated : December 15, 2025

Problem Solution

In this program, we will create an array of integers and then we will sort the created array in ascending order using quicksort.

Program/Source Code

The source code to sort an array in ascending order using quicksort is given below. The given program is compiled and executed successfully.

# Ruby program to sort an array in ascending order 
# using Quick Sort

def QuickSort(arr, first, last)
    pivot= 0;
    temp = 0;
    i    = 0;
    j    = 0;
        
    if(first < last)
            pivot = first;
            i = first;
            j = last;
            
            while(i<j)
                while(arr[i]<=arr[pivot] && i<last)
                    i=i + 1;
                end
                while (arr[j] > arr[pivot])
                    j = j - 1;
                end
                if(i < j)
                    temp   = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                end
            end
            temp = arr[pivot];
            arr[pivot] = arr[j];
            arr[j] = temp;
            QuickSort(arr, first, j - 1);
            QuickSort(arr, j + 1, last);
    end
end

arr = [12,39,49,87,68];

QuickSort(arr,0,4);

i=0;
print "Sorted Array: \n";
while(i<5)
    print arr[i]," ";
    i=i+1;
end

Output

Sorted Array: 
12 39 49 68 87 

Explanation

In the above program, we defined a method QuickSort() to sort an array in ascending order. And, we use recursion to use apply the quick sort process effectively. Using the QuickSort() method, we divide the given array into small sub-arrays. Then we sort sub-arrays recursively.

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