Mastering Nested Loops and String Manipulation in C#

Introduction

Hello and welcome to today's C# lesson! We are going to embark on an intriguing challenge that will test our abilities in string manipulation using a concept known as nested loops . Prepare yourself for an interesting journey as we explore how to extract odd-indexed characters from each word in a sentence, but only if the word has an even number of characters. Let's get started!

Task Statement

Here is a detailed look at our task: We will work with a string that represents a sentence with words separated by spaces. Your objective is to create a C# function that identifies the odd-indexed characters of words that have an even number of characters. Then, combine these characters into a single string, maintaining the order in which they appear in the sentence. Let's consider an example: "CSharp is a high-level programming language." Here, the word CSharp has 6 characters (an even number), so we will select the characters at odd indexes — S, a, p . Similarly, select s from is, and i, h, l, v, and l from high-level . The words a, programming, and language. have odd lengths, so they are skipped. If our function works correctly, it should return "Sapsihlvl." Observe how much information can be extracted from a simple sentence with this process!

Solution Building: Step 1

We start our solution by splitting the sentence into words. In C#, we use the String.Split method to achieve this. The Split method divides the sentence into words at each space, providing us with an array of words. C# using System; public class Solution {public static string SolutionMethod(string sentence) {string[] words = sentence.Split(' '); // we will proceed progressively}}

Solution Building: Step 2

Next, we delve into nested loops : an outer loop iterating over each word and an inner loop checking each character within those words. Firstly, we'll use an if condition to verify if a word has an even length. We find this by using the modulus operator % with 2. If the result is zero, our word has an even length! C# using System; public class Solution {public static string SolutionMethod(string sentence) {string[] words = sentence.Split(' '); foreach (string word in words) {if (word.Length % 2 == 0) // confirms whether the length of the word is even {// we are building up our solution progressively}}}}

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Solution Building: Step 4

Finally, let's add a Main method so you can execute the code and see the function in action. In the Main method, we will define a sample sentence, call the SolutionMethod, and print the result.

using System;
using System.Text;

public class Solution
{
    public static string SolutionMethod(string sentence)
    {
        string[] words = sentence.Split(' ');
        StringBuilder result = new StringBuilder();
        
        foreach (string word in words)
        {
            if (word.Length % 2 == 0) // check if length of word is even
            {
                for (int i = 1; i < word.Length; i += 2) // loop over odd characters
                {
                    result.Append(word[i]);
                }
            }
        }
        return result.ToString();
    }

    public static void Main(string[] args)
    {
        string sentence = "CSharp is a high-level programming language.";
        string result = SolutionMethod(sentence);
        Console.WriteLine(result); // Output: "Sapsihlvl"
    }
}

using System;
using System.Text;

public class Solution
{
    public static string SolutionMethod(string sentence)
    {
        string[] words = sentence.Split(' ');
        StringBuilder result = new StringBuilder();
        
        foreach (string word in words)
        {
            if (word.Length % 2 == 0) // check if length of word is even
            {
                for (int i = 1; i < word.Length; i += 2) // loop over odd characters
                {
                    result.Append(word[i]);
                }
            }
        }
        return result.ToString();
    }

    public static void Main(string[] args)
    {
        string sentence = "CSharp is a high-level programming language.";
        string result = SolutionMethod(sentence);
        Console.WriteLine(result); // Output: "Sapsihlvl"
    }
}

Now, you can run this code to see the solution in practice. The Main method serves as the entry point of the program, where we execute our logic and display the output.