Please help me understand this part

[LightningBlaze]

Hi Everyone,

I want to start off by stating I decided to learn c++ as my first programming language. I understand not many experienced programmers recommend c++ for a complete beginner but I still decided to take on the challenge.

I started reading the book "C++ through game programming" by Michael Dawson. However, during my self-learning journey I find myself confused at the end of chapter 4 with the project Word Jumble. On the section "Jumbling the word" from my understanding the for loop is primarily used for counting or navigating through a sequence of elements. From my observation the value of i within the for loop is not indexed into any array and I don't understand how it is being used here. Also, the int index1 and index2 regenerates a random number from 0 to size number of the generated random word. Correct me if I'm wrong, but if the random chosen word is "wall" then it should be from 0-3 right? Does that mean that the w is considered 0 and the last l is 3? This whole section is very confusing, can anyone explain it to me? I understand the other areas but this part got me stuck. I will really appreciate your time and input towards this case. Thank you very much!

  //The classic word jumble game where the player can ask for a hint


#include <iostream>
#include <string>
#include <cstdlib>
#include <ctime>
using namespace std;

int main()
{
	//Creating the Multidemnsional Array of Words

	enum fields { WORD, HINT, NUM_FIELDS };
	const int NUM_WORDS = 5;
	const string WORDS[NUM_WORDS][NUM_FIELDS] = {

		{ "wall", "Do you fell you're banging your head against something?" },
		{ "glasses", "These might help you see the answer" },
		{ "labored", "Going slowly, is it?" },
		{ "persistent", "keep at it"},
		{ "jumble", "It's what the game is all about" }
	};
	//Selecting random word 
	srand(static_cast<unsigned int>(time(0)));
	int choice = (rand() % NUM_WORDS);
	string theWord = WORDS[choice][WORD];
	string theHint = WORDS[choice][HINT];

	//Jumbling the word
	string jumble = theWord;
	int Length = jumble.size();
	for (int i = 0; i < Length; i++)
	{
		int index1 = (rand() % Length);
		int index2 = (rand() % Length);
		char temp = jumble[index1];
		jumble[index1] = jumble[index2];
		jumble[index2] = temp;
			
	}

	//Welcoming the player
	cout << "\t\t\tWelcome to Word Jumble!\n\n";
	cout << "Unscramble the letters to make a word.\n";
	cout << "Enter 'hint' for a hint.\n";
	cout << "Enter 'quit' to quit the game \n\n";
	cout << "The jumble is: " << jumble;

	string guess;
	cout << "\n\nYour guess : ";
	cin >> guess;

	//Entering the game loop
	while ((guess != theWord)&(guess != "quit"))
	{
		if (guess == "hint")
		{
			cout << theHint;
		}
		else
		{
			cout << "sorry, that's not it";
		}
		cout << "\n\nYour guess: ";
		cin >> guess;
	}

	//Saying Goodbye
	if (guess == theWord)
	{
		cout << "\nThat's it! You guessed it!\n";
	}

	cout << "\nThanks for playing!.\n";
	return 0;
}

[norm b]

All the code in the for loop is doing is scrambling the letters of "theWord".

LightningBlaze wrote:

the for loop is primarily used for counting

Exactly what this loop is used for.

The modulo operator (http://www.cplusplus.com/doc/tutorial/operators/ - scroll down to arithmetic operators) will generate a number between 0 and Length-1.

To see what is happening try putting some cout statements inside the loop:

. . .
      jumble[index2] = temp;
      cout << i << "\t";
      for(int j = 0; j< Length; ++j){
          cout << jumble[j];
      }
      cout << endl;
  }
. . .

[LightningBlaze]

Thank you norm b!. Inserting also the cout command to display index1 and index2 after every loop helped me figured out how the process of jumbling the word took place!