A popular utility for applications.

★★☆

Roly Poly is a classic nursery rhyme for teaching young children opposites such as up and down, big and small, fast and slow. In the rhyme, the word, "up" can be replaced with "big", and the word, "down" replaced with "small" in the second verse.

Make

Write a program that asks the user which word they want to replace in the rhyme: roly poly roly poly up up up roly poly roly poly down down down. The individual words can be stored in an array. All occurrences of that word are replaced with a word chosen by the user.

Note: do not use the Replace method if you are aware of it. You are writing the code that might have been used to make that method.

Success Criteria

Remember to add a comment before a subprogram, selection or iteration statement to explain its purpose.

Complete the subprogram called replace that:

1. Takes three parameters: x is the word to be replaced, y is the word to replace x with, and l is an array of words.
2. Every occurrence of the word x is replaced with the word y.
3. Returns the array.

Complete the subprogram called output that:

1. Takes one parameter, an array of words.
2. Outputs all the words in the array, each one on a new line.

Complete the main program so that:

1. The rhyme is output by calling the output subprogram.
2. The user can input which word to replace.
3. The user can input the new word.
4. The replace subprogram is called to replace the word in the array.
5. The new rhyme is output by calling the output subprogram.

Typical inputs and outputs from the program would be:

roly
poly
roly
poly
up
up
up
roly
poly
roly
poly
down
down
down
Which word to replace? :
up
Replace with what? :
big
roly
poly
roly
poly
big
big
big
roly
poly
roly
poly
down
down
down

// Find and replace program

using System;

class Submission
{
---
    // -------------------------
    // Subprograms
    // -------------------------
    // Function to replace x with y in list l
    static string[] replace(string x, string y, string[] l)
    {
---
        for (int index = 0; index < l.Length; index++)
        {
---
            if (l[index] == x) 
            {
---
                l[index] = y;
---
            } 
---
        }
---
        return l;
---
    }


---
    // Procedure to output the list, each item on a new line
    static void output(string[] l)
    {
---
        foreach(string word in l) {
            Console.WriteLine(word);
        }
---
    }


---
    // -------------------------
    // Main program
    // -------------------------
    public static void Main(string[] args)
    {
---
        string[] rhyme = {"roly", "poly", "roly", "poly", "up", "up", "up", "roly", "poly", "roly", "poly", "down", "down", "down"};
        output(rhyme);
        Console.WriteLine("Which word to replace? :");
        string word = Console.ReadLine();
        Console.WriteLine("Replace with what? :");
        string new_word = Console.ReadLine();
        rhyme = replace(word, new_word, rhyme);
        output(rhyme);
---
    }
}