问题描述
我已经创建了用于描述游戏逻辑的工厂函数。我使用内部函数在游戏中切换玩家。问题是，当我试图从内部函数中重新分配当前球员时，它不起作用。当前的玩家永远不会改变。我想这是关于结束的事情，我并不是真的理解。你能给我解释一下我错过了什么吗？下面是我正在编写的一段代码：
const game = (() => {
let player1 = "Jim";
let player2 = "Mary";
let currentPlayer = player1;
const switchPlayers = () => { //This closure function is supposed to reassign the value of currentPlayer above. But it does not do it.
if (currentPlayer === player1) {
currentPlayer = player2;
} else {
currentPlayer = player1;
}
return currentPlayer;
};
return {currentPlayer, switchPlayers};
})();
game.switchPlayers // works as needed and switches the players every time it is invoked but does not reassign the variable within its parent function;
game.currentPlayer // does not get reassigned, when switchPlayers function is invoked, and returns player1 as was assigned at the start;
推荐答案
您的代码返回 您需要使用如下函数返回值。currentPlayer的值，该值在原始对象的属性更新时不会更新。因此，闭包运行得很好，但事实是您的返回值并没有指向更新后的对象，它只是一个新值，在return语句时将保持不变。
let game = (() => {
let player1 = "Jim";
let player2 = "Mary";
let currentPlayer = player1;
const switchPlayers = () => { //This closure function is supposed to reassign the value of currentPlayer above. But it does not do it.
if (currentPlayer === player1) {
currentPlayer = player2;
} else {
currentPlayer = player1;
}
return currentPlayer;
};
const getCurrentPlayer = () => currentPlayer;
return {
currentPlayer,
switchPlayers,
getCurrentPlayer
};
})();
game.switchPlayers();
console.log(game.currentPlayer);
console.log(game.getCurrentPlayer());
或只需在函数的this指针上定义属性currentPlayer，然后将其用作类型(使用new关键字)，如下所示。
function GameType() {
let player1 = "Jim";
let player2 = "Mary";
this.currentPlayer = player1;
this.switchPlayers = () => { //This closure function is supposed to reassign the value of currentPlayer above. But it does not do it.
if (this.currentPlayer === player1) {
this.currentPlayer = player2;
} else {
this.currentPlayer = player1;
}
return this.currentPlayer;
};
}
let game = new GameType();
console.log(game.currentPlayer);
game.switchPlayers();
console.log(game.currentPlayer);这篇关于为什么我的闭包函数不想在IF语句中重新赋值其父函数变量？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！