Question

我正在写一个类似风险的骰子游戏。这不是整个代码，只是要求玩家姓名的功能。

function getPlayerNames(p1, p2, p3, p4){
    p1 = prompt("What is Player 1's name?", '');p1;
    p2 = prompt("What is Player 2's name?", '');p2;
    p3 = prompt("What is Player 3's name?", '');p3;
    p4 = prompt("What is Player 4's name?", '');p4;
    return;
}

let player1Name, player2Name, player3Name, player4Name;
getPlayerNames(player1Name, player2Name, player3Name, player4Name);

当播放器（1,2,3,4）名称稍后在代码中使用时显示为“未定义”。有什么错误，它没有声明名称，因为它们在提示符中输入，并显示它们未定义？

Answer 1

如评论中所述：JS does not pass by reference, it pass by value

说，这是一个可能的解决方案：
1.在函数内部输入名称 2.返回带有名称的数组 3.将名称分配给变量。

建议：另请阅读Variable Scopes

＆＃13;

function getPlayerNames(){
    let p1 = prompt("What is Player 1's name?", '');
    let p2 = prompt("What is Player 2's name?", '');
    let p3 = prompt("What is Player 3's name?", '');
    let p4 = prompt("What is Player 4's name?", '');
    return [p1,p2,p3,p4];
}

var names = getPlayerNames();    
let player1 = names[0],
player2 = names[1],
player3 = names[2],
player4 = names[3];

console.log("Player 1: " + player1);
console.log("Player 2: " + player2);
console.log("Player 3: " + player3);
console.log("Player 4: " + player4);

＆＃13;

Javascript提示显示为未定义

1 个答案: