Reverse Each Word in a Given String in C#

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How to Reverse Each Word in a Given String in C#

In this article, I am going to discuss How to Reverse Each Word in a Given String in C# with some examples. Please read our previous article where we discussed How to Reverse a String in C# program with some examples. As part of this article, we are going to use the following three approaches to reverse each word in a given string C#.

1. Without using a built-in function
2. Using Stack
3. Using LINQ

Program Description:

The user will input a string and we need to reverse each word individually without changing its position in the string. Here, we will take the input as a string from the user and then we need to reverse each word individually without changing their position in the sentence as shown in the below image.

Method1: Without using any built-in function:

In the following example, we generate all words separated by space. Then reverse the words one by one.

using System;
using System.Collections.Generic;
using System.Text;

namespace LogicalPrograms
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a String : ");
            string originalString = Console.ReadLine();

            StringBuilder reverseWordString = new StringBuilder();
            List<char> charlist = new List<char>();

            for (int i = 0; i < originalString.Length; i++)
            {
                if (originalString[i] == ' ' || i == originalString.Length - 1)
                {
                    if (i == originalString.Length - 1)
                        charlist.Add(originalString[i]);
                    for (int j = charlist.Count - 1; j >= 0; j--)
                        reverseWordString.Append(charlist[j]);

                    reverseWordString.Append(' ');
                    charlist = new List<char>();
                }
                else
                {
                    charlist.Add(originalString[i]);
                }    
            }
            Console.WriteLine($"Reverse Word String : {reverseWordString.ToString()}");
            Console.ReadKey();
        }      
    }
}

Output:

Method2: Using Stack to Reverse Each Word in C#

Here, we are using a stack to push all words before space. Then as soon as we encounter a space, we empty the stack. The program is self-explained, so please go through the comments line.

using System;
using System.Collections.Generic;

namespace LogicalPrograms
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a String : ");
            string originalString = Console.ReadLine();

            Stack<char> charStack = new Stack<char>();

            // Traverse the given string and push all characters
            // to stack until we see a space.  
            for (int i = 0; i < originalString.Length; ++i)
            {
                if (originalString[i] != ' ')
                {
                    charStack.Push(originalString[i]);
                }

                // When seeing a space, then print contents of the stack.  
                else
                {
                    while (charStack.Count > 0)
                    {
                        Console.Write(charStack.Pop());
                    }
                    Console.Write(" ");
                }
            }

            // Since there may not be space after last word.  
            while (charStack.Count > 0)
            {
                Console.Write(charStack.Pop());
            }
            
            Console.ReadKey();
        }      
    }
}

Method3: Using Linq to Reverse Each Word in C#

using System;
using System.Linq;

namespace LogicalPrograms
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a String : ");
            string originalString = Console.ReadLine();
            
            string reverseWordString = string.Join(" ", originalString
            .Split(' ')
            .Select(x => new String(x.Reverse().ToArray())));

            Console.WriteLine($"Reverse Word String : {reverseWordString}");
            Console.ReadKey();
        }      
    }
}

Output:

Code Explanation:

Split the input string using a single space as the separator.

The Split method is used for returning a string array that contains each word of the input string. We use the Select method for constructing a new string array, by reversing each character in each word. Finally, we use the Join method for converting the string array into a string.

In the next article, I am going to discuss How to Remove Duplicate Characters from a given string in C# using different mechanisms. I hope now you understood How to Reverse Each Word in a Given String in C# with different mechanisms.