将变量更改为全局，以便外部警报功能可以使用它

Question

I am writing a little game (rock-scissors-paper) in JavaScript for my school as a home project and recently I got stuck. I am trying to change the original ( let ) variables to global variables so their value can be seen by the outer function. The value of pScore is increased in each round, the score gets updated.

I have tried to change the variable from let to var , but it was not working.

const game = () => {
    let pScore = 0; //player score
    let cScore = 0; //computer score
    var mScore = 12; // maximal score

    // the Function
    const updateScore = () => {
        const playerScore = document.querySelector(".player-score p");
        const computerScore = document.querySelector(".computer-score p");
        playerScore.textContent = window.pScore;
        computerScore.textContent = cScore;
    };

    //Check for Paper
    if (playerChoice === "paper") {
        if (computerChoice === "scissors") {
            winner.textContent = "computer wins! :(";
            cScore++;
            updateScore();
            return;
        } else {
            winner.textContent = "you won! :)";
            pScore++;
            updateScore();
            if (pScore === mScore) {
                finalScore();
            }
            return;
        }
    }
};

//The Outer function
function timer() {
    var countDown = new Date(Date.now() + 60000).getTime();
    var x = setInterval(
        function () {
            var now = new Date().getTime();
            var distance = countDown - now;

            var seconds = Math.floor((distance % (1000 * 60)) / 1000);

            document.getElementById("timer").innerHTML = seconds;

            if (distance < 0) {
                clearInterval(x);
                alert(un + ' Time is up!' + alert(playerScore.textContent));
                location.reload(true);
            }
        }, 1000
    );
}

error: pScore or playerScore is not defined

I would like the countdown function to reach pScore, then Alert the last updated score.

Answer 1

I've rearrange your code slightly to make it work.

Changes

• Removed the window. part from window.pScore . The pScore variable is not truly global but rather is global within the game() function.
• Moved the playerScore and computerScore variables out of the game() function and made them accessible to the timer() function

    const playerScore = document.querySelector(".player-score p");
    const computerScore = document.querySelector(".computer-score p");
    const game = () => {
    let pScore = 0; //player score
    let cScore = 0; //computer score
    var mScore = 12; // maximal score

    // the Function
    const updateScore = () => {
        playerScore.textContent = pScore;
        computerScore.textContent = cScore;
    };

    //Check for Paper
    if (playerChoice === "paper") {
        if (computerChoice === "scissors") {
            winner.textContent = "computer wins! :(";
            cScore++;
            updateScore();
            return;
        } else {
            winner.textContent = "you won! :)";
            pScore++;
            updateScore();
            if (pScore === mScore) {
                finalScore();
            }
            return;
            }
        }
    };

//The Outer function
function timer() {
    var countDown = new Date(Date.now() + 60000).getTime();
    var x = setInterval(
        function () {
            var now = new Date().getTime();
            var distance = countDown - now;

            var seconds = Math.floor((distance % (1000 * 60)) / 1000);

            document.getElementById("timer").innerHTML = seconds;

            if (distance < 0) {
                clearInterval(x);
                alert(un + ' Time is up!' + alert(playerScore.textContent));
                location.reload(true);
            }
        }, 1000
    );
}