Now that we have the core gameplay down, we'll want to implement logic to allow the secretNumber to be chosen at random. To do this, we'll utilize the Math#random method. Take a look at the docs. The method returns a decimal number between 0 and 1 (excluding 1).
For example:
console.log(Math.random()); // 0.5719957072947224
console.log(Math.random()); // 0.08590173924968769
console.log(Math.random()); // 0.0965770175443883
By itself, this method won't be too useful because our game should only use whole numbers. Luckily, the docs provide some insight into how we can design a function that returns a random whole number that lies within a certain range. Scroll through the docs and locate examples about "Getting a random integer between two values." You'll use these examples to inspire your code. You may notice that the examples provided rely on other methods like Math.floor. Research those methods so that you understand how the code works. Googling around and researching the docs is an important aspect of being a developer, so take your time!
Define a function called randomInRange that accepts a minimum and maximum number as arguments. The function should return a random whole number between the provided minimum and maximum (inclusive). Be sure to test your function, here is an example of how it might behave:
console.log(randomInRange(15, 20)); // 16
console.log(randomInRange(15, 20)); // 17
console.log(randomInRange(15, 20)); // 20
Once you have confirmed that your randomInRange function is returning numbers properly, edit your initialization of secretNumber. Instead of setting it to a hard-coded value, use your function's return value to set it to a random number between 0 and 100. Play a few games! Remember that you'll have to call askGuess() once in the global scope to begin the game. Next up, we'll allow the user to choose the min and max for the game.
Delete or comment out your global call to askGuess for now. Define a function called askRange. This method should ask the user to enter a minimum number and then ask them to enter a maximum number. We want to ask them for the maximum only after they have responded to the first question. This means you will have to use the question method twice! Recall what you learned from the readings. The question method is asynchronous, so how can we ask two questions one after the other? We'll leave the implementation to you. After the user enters their min and max, you should print a message confirming the range. Here is an example of how our askRange method behaves. We've put asterisks around the user's input:
Enter a max number: 20
Enter a min number: 11
I'm thinking of a number between 11 and 20...
As always, test your function thoroughly by adding a call to askRange in global scope. Your program may hang because the interface is not closed after the user enters their max. That's okay, since we are debugging; press ctrl + c in your terminal to kill the program.
Once your function is able to properly take the min and max from your user, it's time to put it all together! When the user enters both the min and the max, call your randomInRange function with that min and max as arguments. Recall that the user's input is automatically interpreted as strings and not numbers. You should explicitly turn the min and max to actual numbers before passing them in. Take the random number returned from your function and set that as the secretNumber. Then call your old askGuess method so that gameplay can begin. All of this should happen within the askRange function. We design it this way because we only want to ask for a guess after the random number has been chosen.
The askRange function is the "main" function that will begin our game, so you'll need call it once in the global scope. Run your program and play a few games!
With our main features complete, let's work on increasing the difficulty of the game by limiting the number of guesses a user can make. If the player uses all of their attempts without guessing the correct number, they will lose the game.
Start by limiting the player to 5 attempts. You can accomplish this by initializing a numAttempts variable in the global scope. Refactor your askGuess method to decrement the number of remaining attempts whenever it is called. If the numAttempts reaches 0 before the correct guess is made, end the game by printing 'You Lose'. We'll leave the details of the implementation up to you.
Make the limit dynamic by allowing the user to specify the number of attempts. We recommend creating an askLimit function that behaves similarly to askRange. Be sure to chain the callbacks in the right order to ensure the game is configured properly. For example, one valid callback chain order would be askLimit -> askRange -> askGuess. If you follow this order, you'll need to call askLimit in the global scope to begin the game.