Great day to all!

I was wondering why if I already chose "rock" (in the const playerSelection) and computer chose "rock" it prints me out that the "Computer wins" or sometimes it prints out that I won the game instead of being a tie. Same goes with the other element in the code.

What would have happened that made the result of the game to also be randomized?

Here is my code:

function computerPicks() {
 let compChoices = ["rock", "paper", "scissors"] // let computer pick [rock, paper, scissors]
 let randomizeChoice = Math.floor(Math.random() * compChoices.length)   1 // randomize rock paper and scissors

 if (randomizeChoice === 1) {
   return "rock";
 } if (randomizeChoice === 2) {
   return "paper";
 } if (randomizeChoice === 3) {
   return "scissors";
 }
}

console.log(computerPicks()); // view computer's choice


function playRound(playerSelection, computerSelection) {
  if (playerSelection === "rock") {  
    if (computerSelection === "rock") {
      return "It is a tie!!"
    } else if (computerSelection === "paper") {
        return "The computer wins!";
      } else {
        return "You win this game!";
      }
  }
  else if (playerSelection === "paper") {  
    if (computerSelection === "paper") {
      return "It is a tie!!"
    } else if (computerSelection === "rock") {
        return "The computer wins!";
      } else {
        return "You win this game!";
      }
  } else {
    if (computerSelection === "rock") {
      return "Computer wins!";
  } else if (computerSelection === "paper") {
      return "User wins!";
  } else {
      return "Draw!";
  }
  }


}

const playerSelection = "scissors"; // primary choice
const computerSelection = computerPicks(); // calls the randomized choices
console.log(playRound(playerSelection, computerSelection)); // print out the result

I think it is also randomizing because of how I called the randomizer or on how it is declared in the computerPicks() function.

CodePudding user response：

The question has been correctly answered, so this is just a suggestion of what changes you might make to your game that could simplify things.

Dealing with many levels of if/else statements can be difficult to comprehend, maintain, and debug.

You could reduce a lot of the complexity by storing some of the engine logic in an object that defines which choices beat which choices (see poorly named whatBeatsWhat).

// Explicit mapping of winning key (i.e. "rock") beating losing value (i.e. "scissors").
const whatBeatsWhat = {
  rock: "scissors",
  paper: "rock",
  scissors: "paper",
}

// Derive computerChoices from keys of whatBeatsWhat.
const computerChoices = Object.keys(whatBeatsWhat)

function computerPicks() {
  // Randomize rock paper and scissors.
  let randomizeChoice = Math.floor(Math.random() * computerChoices.length)
  // randomizeChoice will be one of [0,1,2] representing all possible indices of computerChoices.
  return computerChoices[randomizeChoice]
}

function playRound(playerSelection, computerSelection) {
  if (playerSelection === computerSelection) {
    return "It is a tie!!"
  }

  // Check if playerSelection in whatBeatsWhat maps to computerSelection
  // and if so, player has beaten computer.
  if (whatBeatsWhat[playerSelection] === computerSelection) {
    return "You win this game!"
  }

  // Undoubtedly, whatBeatsWhat[computerSelection] === playerSelection
  return "The computer wins!"
}

const playerSelection = "scissors"
const computerSelection = computerPicks()
const result = playRound(playerSelection, computerSelection)
console.log(`${result} (${playerSelection} vs ${computerSelection})`)

CodePudding user response：

Your program is not behaving as expected because you are using the '===' operator to compare strings. The '===' operator is a strict equality operator, meaning that it will only return true if both operands refer to the same object. In your case, '==' would be more appropriate since you are checking for basic equality.