如何在函式內更改全域變數的值

我知道以前有人問過這個問題，但我的情況似乎有點不同

我有兩個 js 檔案，一個用于邏輯，一個用于包含有關電影資料的物件

我的第一個檔案看起來像這樣

var movieTitle = document.getElementById("movieTitle");
var rating = document.getElementById("rating");
var movieYear = document.getElementById("movieYear");
var movieDuration = document.getElementById("movieDuration");
var actorName = document.getElementById("actorName");
var actorRole = document.getElementById("actorRole");
var actorNameI = document.getElementById("actorName2");
var actorRoleII = document.getElementById("actorRole2");
var testClick = document.getElementById("testClick");

var movie = movieI;

movieTitle.innerHTML = "Title: "   movie.title;
movieYear.innerHTML = "release Year: "   movie.releaseYear;
movieDuration.innerHTML = "Duration: "   movie.duration;

actorName.innerHTML = "Name: "   movie.actors[0].name;
actorRole.innerHTML = "Role: "   movie.actors[0].role;

actorNameI.innerHTML = "Name: "   movie.actors[1].name;
actorRoleII.innerHTML = "Role: "   movie.actors[1].role;

rating.innerHTML = "Rating: "   movie.rating;

testClick.addEventListener("click", function(){
    var movie = movieII
})

我從中獲取物件的檔案看起來像這樣

var movieI = {
    title: "Titanic",
    releaseYear: 1997,
    rating: "PG21",
    duration: "3 hours",

    actors: [

    {
        name: "leonardo dicaprio",
        role: "role goes here"
    },

    {
        name: "kate winslet",
        role: "role goes here"
    },

    ]
};


var movieII = {
    title: "Wolf of wall street",
    releaseYear: 2013,
    rating: "PG18",
    duration: "2H 30M",

    actors: [

    {
        name: "leonardo dicaprio",
        role: "role goes here"
    },

    {
        name: "jonah hill",
        role: "role goes here"
    },

    ]
};

在我的第一個 js 檔案中，我有以下功能

testClick.addEventListener("click", function(){
    movie = movieII
})

這應該修改電影變數的值并將其設定為movieII，以便它可以從我的物件檔案中切換/訪問第二個物件（movieII），但它似乎不起作用。

uj5u.com熱心網友回復：

你有沒有嘗試在這個專案中使用函式和引數？

這是js中的檔案 函式

uj5u.com熱心網友回復：

您的問題是更新物件不會更改 HTML 中已經顯示的內容，您需要使用新資訊更新您的 HTML，但前提是它在變數中發生更改。

您可以做到這一點（就像您在代碼中所做的那樣），或者只是創建一個您每次都可以呼叫的函式，這將幫助您避免重復代碼。

這是您可以做到的一種方法：

//Titanic

let movieI = {
    title: "Titanic",
    releaseYear: 1997,
    rating: "PG21",
    duration: "3 hours",

    actors: [

    {
        name: "leonardo dicaprio",
        role: "role goes here"
    },

    {
        name: "kate winslet",
        role: "role goes here"
    },

    ]
};


let movieII = {
    title: "Wolf of wall street",
    releaseYear: 2013,
    rating: "PG18",
    duration: "2H 30M",

    actors: [

    {
        name: "leonardo dicaprio",
        role: "role goes here"
    },

    {
        name: "jonah hill",
        role: "role goes here"
    },

    ]
};

let actorsBox = document.getElementById("actos-box");
let movieTitle = document.getElementById("movieTitle");
let rating = document.getElementById("rating");
let movieYear = document.getElementById("movieYear");
let movieDuration = document.getElementById("movieDuration");
let actorName = document.getElementById("actorName");
let actorRole = document.getElementById("actorRole");
let actorNameI = document.getElementById("actorName2");
let actorRoleII = document.getElementById("actorRole2");
let testClick = document.getElementById("testClick");

let movie = movieI;

updateMovie();


testClick.addEventListener("click", function(){
    movie = movieII
  updateMovie();
})

function updateMovie(){
  movieTitle.innerHTML = "Title: "   movie.title;
  movieYear.innerHTML = "release Year: "   movie.releaseYear;
  movieDuration.innerHTML = "Duration: "   movie.duration;

  actorName.innerHTML = "Name: "   movie.actors[0].name;
  actorRole.innerHTML = "Role: "   movie.actors[0].role;

  actorNameI.innerHTML = "Name: "   movie.actors[1].name;
  actorRoleII.innerHTML = "Role: "   movie.actors[1].role;

  rating.innerHTML = "Rating: "   movie.rating;
}

另外，我強烈建議您不要使用 var，因為它可能會做一些您可能不想做的奇怪事情。

看看這個以了解更多關于 let 變數的資訊。

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