遍歷陣列的更好方法

我是 javascript 新手，我被要求這樣做；任務：根據電影名稱和發行日期創建一個至少包含五個物件的陣列。標題 發行日期 Jaws 1975 ET 1982 Psycho 1960 IT 1990 Vertigo 1958

然后，創建一個回圈遍歷陣列，在警告框中顯示用戶輸入一年后發布的電影。例如，如果用戶鍵入“1978”，則警告框將僅顯示 ET 和 IT 的電影標題。

這是我這樣做的方式，但我確信有更好的方法，所以我尋求一點幫助！謝謝 ：）

movies = ["Vertigo", " Psycho", " Jaws", " E.T", " IT"];
year = ["1958", "1960", "1975", "1982", "1990"];


userInput = prompt("Enter the year of movies you are interested in viewing\nYear: ");
  alert("The year you have selected is "   userInput);

for (movie in movies) {
  if (userInput == year[0]) {
    alert("Here are a list of movies released after; "   userInput);
    alert(movies); 
    break;
  }
  if (userInput == year[1]) {
    alert("Here are a list of movies released after; "   userInput);
    alert(movies[1]   movies[2]   movies[3]   movies[4]); 
    break;
  }
  if (userInput == year[2]) {
    alert("Here are a list of movies released after; "   userInput);
    alert(movies[2], movies[3], movies[4]); 
    break;
  }
  if (userInput == year[3]) {
    alert("Here are a list of movies released after; "   userInput);
    alert(movies[3], movies[4]); 
    break;
  }
  if (userInput == year[4]) {
    alert("Here are a list of movies released after; "   userInput);
    alert(movies[4]); 
    break;
  }
  else {
    alert("There are no movies. Please input the correct information and try again.");
    break;
  }
}
}

uj5u.com熱心網友回復：

有一個更好的方法：

首先根據用戶輸入過濾電影：

const filteredYears = year.filter(item => Number(item) >= Number(userInput);

然后獲取每個過濾年份的電影。

// Loop the filtered years
filteredYears.forEach(year => {
    // Get the index of current element
    const index = year.findIndex(y => y === year);

    // Just in case, if year found
    if ( index !== -1 ){
        alert("Here are a list of movies released after; "   userInput);
        // The movie of this year.
        alert(movies[index]);
    } 
});

uj5u.com熱心網友回復：

基本上，您撰寫了一個硬代碼，將所有這些年份和電影名稱包裝在 obj 中，并在每個鍵和值中回圈。

movies = {
    1958 : "Vertigo",
    1960 : " Psycho",
    1975 : " Jaws",
    1982 : " E.T",
    1990 : " IT",
}

userInput = prompt("Enter the year of movies you are interested in viewing\nYear: ");
alert("The year you have selected is "   userInput);

Object.entries(movies).forEach(
    ([key, value]) => key < userInput &&  alert("Here are a list of movies released after; "   value));

uj5u.com熱心網友回復：

嘗試使用電影物件：

movies = [
  {
    title:"Vertigo",
    year:1958
  },
   {
    title:"Psycho",
    year:1960
  },
   {
    title:"Jaws",
    year:1975
  }, {
    title:"E.T",
    year:1982
  }, {
    title:"IT",
    year:1990
  }
]

userInput = prompt("Enter the year of movies you are interested in viewing\nYear: ");
alert("The year you have selected is "   userInput);

//filter movies by year from userInput
const selectedMovies=movies.filter((movie)=>movie.year>=parseInt(userInput));

//check if any movie in array
if(selectedMovies.length){
  alert("Here are a list of movies released after: "   userInput);
  //get only movies titles to array
  const moviesTitlesToDisplay=selectedMovies.reduce((list,movie)=> list.concat(movie.title),[]);
  alert(moviesTitlesToDisplay);
} else {
  alert("There are no movies. Please input the correct information and try again.");
}

CodePen 示例：https ://codepen.io/marcinbzone/pen/popYBaJ

標籤：javascript

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