我有一个包含问题的对象，每个问题都有一个不同的难度，用allQuiz[x].difficulty表示。
我写了一个for循环，它将按其相对难度类别对问题进行排序。例如，难度25 =容易，难度50 =中等。
这是对象结构的一部分：
{
"id": "41",
"category": "TV & Movies",
"locales": "GB#US",
"difficulty": "50",
"question": {
"Voice": "Which fictional city is the home of Batman?",
"Display": "Which fictional city is the home of Batman?"
},
"answer": {
"Voice": "Gotham City",
"Display": "Gotham City"
}
},
{
"id": "42",
"category": "TV & Movies",
"locales": "GB#US",
"difficulty": "50",
"question": {
"Voice": "The Hunchback of Notre Dame was also known as?",
"Display": "The Hunchback of Notre Dame was also known as?"
},
"answer": {
"Voice": "Quasimodo",
"Display": "Quasimodo"
}
},
{
"id": "43",
"category": "TV & Movies",
"locales": "GB#US",
"difficulty": "75",
"question": {
"Voice": "The title role of the 1990 movie Pretty Woman was played by which actress?",
"Display": "The title role of the 1990 movie Pretty Woman was played by which actress?"
},
"answer": {
"Voice": "Julia Roberts",
"Display": "Julia Roberts"
}
},
{
"id": "44",
"category": "TV & Movies",
"locales": "GB#US",
"difficulty": "75",
"question": {
"Voice": "Which Tom Hanks movie won the Academy Award for Best Picture in 1994?",
"Display": "Which Tom Hanks movie won the Academy Award for Best Picture in 1994?"
},
"answer": {
"Voice": "Forrest Gump",
"Display": "Forrest Gump"
}
},
{
"id": "45",
"category": "TV & Movies",
"locales": "GB#US",
"difficulty": "100",
"question": {
"Voice": "Jonny Depp starred as Jack Sparrow in which series of movies?",
"Display": "Jonny Depp starred as Jack Sparrow in which series of movies?"
},
"answer": {
"Voice": "Pirates of the Caribbean",
"Display": "Pirates of the Caribbean"
}
},
{
"id": "46",
"category": "TV & Movies",
"locales": "GB#US",
"difficulty": "100",
"question": {
"Voice": "Marion Crane is the tragic figure in which cult horror film?",
"Display": "Marion Crane is the tragic figure in which cult horror film?"
},
"answer": {
"Voice": "Psycho",
"Display": "Psycho"
}
},
{
"id": "47",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "25",
"question": {
"Voice": "Alexander Graham Bell invented which communication tool?",
"Display": "Alexander Graham Bell invented which communication tool?"
},
"answer": {
"Voice": "Telephone",
"Display": "Telephone"
}
},
{
"id": "48",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "75",
"question": {
"Voice": "Steve jobs was the founder of which tech giant?",
"Display": "Steve jobs was the founder of which tech giant?"
},
"answer": {
"Voice": "Apple",
"Display": "Apple"
}
},
{
"id": "49",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "75",
"question": {
"Voice": "Which year was Amazon founded?",
"Display": "Which year was Amazon founded?"
},
"answer": {
"Voice": "1994",
"Display": "1994"
}
},
{
"id": "50",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "100",
"question": {
"Voice": "What is the natural habitat of an arboreal creature?",
"Display": "What is the natural habitat of an arboreal creature?"
},
"answer": {
"Voice": "Trees",
"Display": "Trees"
}
},
{
"id": "51",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "25",
"question": {
"Voice": "What is a geiger counter used to detect?",
"Display": "What is a geiger counter used to detect?"
},
"answer": {
"Voice": "Radiation",
"Display": "Radiation"
}
},
{
"id": "52",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "50",
"question": {
"Voice": "What element on the periodic table has the chemical symbol H?",
"Display": "What element on the periodic table has the chemical symbol H?"
},
"answer": {
"Voice": "Hydrogen",
"Display": "Hydrogen"
}
},
{
"id": "53",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "50",
"question": {
"Voice": "What is the more common name for Nitrous Oxide? �",
"Display": "What is the more common name for Nitrous Oxide? �"
},
"answer": {
"Voice": "Laughing gas",
"Display": "Laughing gas"
}
},
{
"id": "54",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "75",
"question": {
"Voice": "In computing, how many bits are in a byte?",
"Display": "In computing, how many bits are in a byte?"
},
"answer": {
"Voice": "Eight",
"Display": "Eight"
}
},
{
"id": "55",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "50",
"question": {
"Voice": "Who discovered Penicillin?",
"Display": "Who discovered Penicillin?"
},
"answer": {
"Voice": "Alexander Fleming",
"Display": "Alexander Fleming"
}
},
{
"id": "56",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "25",
"question": {
"Voice": "Which planet in our solar system is closest to the sun?",
"Display": "Which planet in our solar system is closest to the sun?"
},
"answer": {
"Voice": "Mercury",
"Display": "Mercury"
}
},
{
"id": "57",
"category": "Science & Technology",
"locales": "GB#US",
"difficulty": "25",
"question": {
"Voice": "What subject did Mark Zuckerburg study at university?",
"Display": "What subject did Mark Zuckerburg study at university?"
},
"answer": {
"Voice": "Computer Science",
"Display": "Computer Science"
}
},
这是我的尝试：
var allQuiz= myObject;
var easyQuiz =[];
var mediumQuiz =[];
var hardQuiz =[];
var veryhardQuiz =[];
for(let x=0;x<allQuiz.length;x++){
if(allQuiz[x].difficulty==25){
let tmp = [];
tmp.push((allQuiz[x]).id);
tmp.push((allQuiz[x]).question.Display);
tmp.push((allQuiz[x]).answer.Display);
easyQuiz.push(tmp);
}
else if(allQuiz[x].difficulty==50){
let tmp =[];
tmp.push((allQuiz[x]).id);
tmp.push((allQuiz[x]).question.Display);
tmp.push((allQuiz[x]).answer.Display);
mediumQuiz.push(tmp);
}
else if(allQuiz[x].difficulty==75){
let tmp =[];
tmp.push((allQuiz[x]).id);
tmp.push((allQuiz[x]).question.Display);
tmp.push((allQuiz[x]).answer.Display);
hardQuiz.push(tmp);
}
else {
let tmp = [];
tmp.push((allQuiz[x]).id);
tmp.push((allQuiz[x]).question.Display);
tmp.push((allQuiz[x]).answer.Display);
veryhardQuiz.push(tmp);
}
}
但是，我注意到这里有很多重复的代码，改变的唯一因素是即时推送到的测验类别以及问题的难度。
如何使此for循环更优雅或更有效？
答案 0 :(得分：2)
在不牺牲可读性的前提下，我认为我不能使其更加简洁：
var allQuiz= myObject;
var quizzesByDifficulty = { 25: [], 50: [], 75: [], 100: [] };
for(var x in allQuiz)
{
var quiz = allQuiz[x];
var quizzes = quizzesByDifficulty[quiz.difficulty];
quizzes.push([
quiz.id,
quiz.question.Display,
quiz.answer.Display
]);
}
如果您需要将每个难度作为自己的数组，则可以始终这样做：
var easy = quizzesByDifficult[25];
var medium = quizzesByDifficulty[50];
// etc.
编辑：当然，以上假设仅存在4个困难。如果这是您无法做出的假设，则仍然可以修改代码以解决该问题：
var allQuiz= myObject;
var quizzesByDifficulty = {};
for(var x in allQuiz)
{
var quiz = allQuiz[x];
if (!quizzesByDifficulty[quiz.difficulty]) {
quizzesByDifficulty[quiz.difficulty] = [];
}
var quizzes = quizzesByDifficulty[quiz.difficulty];
quizzes.push([
quiz.id,
quiz.question.Display,
quiz.answer.Display
]);
}
答案 1 :(得分：1)
array.reduce是用于此类数据转换任务的便捷功能。这个想法是创建一个难度映射到值数组的键对象。最后，可以将生成的对象拆分为四个所需的结构或按原样使用（如果需要，可以将键从难度编号映射到难度词）。
var allQuiz = [{ "id": "41", "category": "TV & Movies", "locales": "GB#US", "difficulty": "50", "question": { "Voice": "Which fictional city is the home of Batman?", "Display": "Which fictional city is the home of Batman?" }, "answer": { "Voice": "Gotham City", "Display": "Gotham City" } }, { "id": "42", "category": "TV & Movies", "locales": "GB#US", "difficulty": "50", "question": { "Voice": "The Hunchback of Notre Dame was also known as?", "Display": "The Hunchback of Notre Dame was also known as?" }, "answer": { "Voice": "Quasimodo", "Display": "Quasimodo" } }, { "id": "43", "category": "TV & Movies", "locales": "GB#US", "difficulty": "75", "question": { "Voice": "The title role of the 1990 movie Pretty Woman was played by which actress?", "Display": "The title role of the 1990 movie Pretty Woman was played by which actress?" }, "answer": { "Voice": "Julia Roberts", "Display": "Julia Roberts" } }, { "id": "44", "category": "TV & Movies", "locales": "GB#US", "difficulty": "75", "question": { "Voice": "Which Tom Hanks movie won the Academy Award for Best Picture in 1994?", "Display": "Which Tom Hanks movie won the Academy Award for Best Picture in 1994?" }, "answer": { "Voice": "Forrest Gump", "Display": "Forrest Gump" } }, { "id": "45", "category": "TV & Movies", "locales": "GB#US", "difficulty": "100", "question": { "Voice": "Jonny Depp starred as Jack Sparrow in which series of movies?", "Display": "Jonny Depp starred as Jack Sparrow in which series of movies?" }, "answer": { "Voice": "Pirates of the Caribbean", "Display": "Pirates of the Caribbean" } }, { "id": "46", "category": "TV & Movies", "locales": "GB#US", "difficulty": "100", "question": { "Voice": "Marion Crane is the tragic figure in which cult horror film?", "Display": "Marion Crane is the tragic figure in which cult horror film?" }, "answer": { "Voice": "Psycho", "Display": "Psycho" } }, { "id": "47", "category": "Science & Technology", "locales": "GB#US", "difficulty": "25", "question": { "Voice": "Alexander Graham Bell invented which communication tool?", "Display": "Alexander Graham Bell invented which communication tool?" }, "answer": { "Voice": "Telephone", "Display": "Telephone" } }, { "id": "48", "category": "Science & Technology", "locales": "GB#US", "difficulty": "75", "question": { "Voice": "Steve jobs was the founder of which tech giant?", "Display": "Steve jobs was the founder of which tech giant?" }, "answer": { "Voice": "Apple", "Display": "Apple" } }, { "id": "49", "category": "Science & Technology", "locales": "GB#US", "difficulty": "75", "question": { "Voice": "Which year was Amazon founded?", "Display": "Which year was Amazon founded?" }, "answer": { "Voice": "1994", "Display": "1994" } }, { "id": "50", "category": "Science & Technology", "locales": "GB#US", "difficulty": "100", "question": { "Voice": "What is the natural habitat of an arboreal creature?", "Display": "What is the natural habitat of an arboreal creature?" }, "answer": { "Voice": "Trees", "Display": "Trees" } }, { "id": "51", "category": "Science & Technology", "locales": "GB#US", "difficulty": "25", "question": { "Voice": "What is a geiger counter used to detect?", "Display": "What is a geiger counter used to detect?" }, "answer": { "Voice": "Radiation", "Display": "Radiation" } }, { "id": "52", "category": "Science & Technology", "locales": "GB#US", "difficulty": "50", "question": { "Voice": "What element on the periodic table has the chemical symbol H?", "Display": "What element on the periodic table has the chemical symbol H?" }, "answer": { "Voice": "Hydrogen", "Display": "Hydrogen" } }, { "id": "53", "category": "Science & Technology", "locales": "GB#US", "difficulty": "50", "question": { "Voice": "What is the more common name for Nitrous Oxide? �", "Display": "What is the more common name for Nitrous Oxide? �" }, "answer": { "Voice": "Laughing gas", "Display": "Laughing gas" } }, { "id": "54", "category": "Science & Technology", "locales": "GB#US", "difficulty": "75", "question": { "Voice": "In computing, how many bits are in a byte?", "Display": "In computing, how many bits are in a byte?" }, "answer": { "Voice": "Eight", "Display": "Eight" } }, { "id": "55", "category": "Science & Technology", "locales": "GB#US", "difficulty": "50", "question": { "Voice": "Who discovered Penicillin?", "Display": "Who discovered Penicillin?" }, "answer": { "Voice": "Alexander Fleming", "Display": "Alexander Fleming" } }, { "id": "56", "category": "Science & Technology", "locales": "GB#US", "difficulty": "25", "question": { "Voice": "Which planet in our solar system is closest to the sun?", "Display": "Which planet in our solar system is closest to the sun?" }, "answer": { "Voice": "Mercury", "Display": "Mercury" } }, { "id": "57", "category": "Science & Technology", "locales": "GB#US", "difficulty": "25", "question": { "Voice": "What subject did Mark Zuckerburg study at university?", "Display": "What subject did Mark Zuckerburg study at university?" }, "answer": { "Voice": "Computer Science", "Display": "Computer Science" } },];
const quizzes = allQuiz.reduce((a, e) => {
if (!a[e.difficulty]) {
a[e.difficulty] = [];
}
a[e.difficulty].push([e.id, e.question.Display, e.answer.Display]);
return a;
}, {});
const easyQuiz = quizzes["25"];
const mediumQuiz = quizzes["50"];
const hardQuiz = quizzes["75"];
const veryHardQuiz = quizzes["100"];
console.log(easyQuiz);
console.log(mediumQuiz);
console.log(hardQuiz);
console.log(veryHardQuiz);
答案 2 :(得分：0)
我假设allQuiz将是一个数组。是的，就像您提到的那样，可以进行很多优化。
const allQuiz = [{
id: 1,
question: {
Display: 'abc'
},
answer: {
Display: '123'
},
difficulty: 25
}];
const sortedQuiz = {
easyQuiz: [],
mediumQuiz: [],
hardQuiz: [],
veryhardQuiz: [],
}
allQuiz.reduce((acc, quiz) => {
let category;
// Following if..else can also be pulled out into a seperate function
if (quiz.difficulty === 25) {
category = acc.easyQuiz;
} else if (quiz.difficulty === 50) {
category = acc.mediumQuiz;
} else if (quiz.difficulty === 75) {
category = acc.hardQuiz;
} else {
category = acc.veryhardQuiz;
}
category.push([quiz.id, quiz.question.Display, quiz.answer.Display]);
return acc;
}, sortedQuiz)
const appDiv = document.getElementById('app');
appDiv.innerHTML = `<p>${JSON.stringify(sortedQuiz)}</p>`;<div id="app"></div>