[英]React – Create array from arrays in Objects
初學者 React/JS 問題在這里。 我有一系列條目(表單提交),每個條目都包含 arrays 語言,如下所示:
0: {…}
dream: Array [ "Bengali", "French" ]
feel: Array [ "Arabic", "English" ]
speak: Array [ "Afrikaans", "Armenian" ]
think: Array [ "Albanian" ]
1: {…}
dream: Array [ "English", "French" ]
feel: Array [ "German", "Italian" ]
speak: Array [ "Afrikaans", "English" ]
think: Array [ "Cantonese" ]
我想要每個類別中所有語言的數組。 我知道我必須過濾每個條目並保存語言,但我不知道如何檢查重復項。
目前,我可以使用過濾器查看單一語言的條目
setFilter(entries.filter((key) => key.speak.includes("Afrikaans")));
但我不知道如何創建所有語言的主列表。
這是你想要的嗎? 您需要減少和過濾以避免重復,結果您將獲得 object
const myArray = [{ dream: [ "Bengali", "French" ], feel: [ "Arabic", "English" ], speak: [ "Afrikaans", "Armenian" ], think: [ "Albanian" ] },{ dream: [ "Bengaslis", "French" ], feel: [ "Arabsic", "English" ], speak: [ "Afrikasans", "Armenian" ], think: [ "Assslbanian" ] } ]; const result = myArray.reduce((accumulator, currentValue) => { const dream = accumulator.dream.concat(currentValue.dream); const think = accumulator.think.concat(currentValue.think); const feel = accumulator.feel.concat(currentValue.feel); const speak = accumulator.speak.concat(currentValue.speak); accumulator.dream = dream.filter((item, pos) => dream.indexOf(item) === pos) accumulator.feel = feel.filter((item, pos) => feel.indexOf(item) === pos); accumulator.speak = speak.filter((item, pos) => speak.indexOf(item) === pos); accumulator.think = think.filter((item, pos) => think.indexOf(item) === pos); return accumulator; }) console.log(result)
您可以使用Object.values
和Object.entries
來遍歷數據 object。
const data = { 0: { dream: ["Bengali", "French"], feel: ["Arabic", "English"], speak: ["Afrikaans", "Armenian"], think: ["Albanian"], }, 1: { dream: ["English", "French"], feel: ["German", "Italian"], speak: ["Afrikaans", "English"], think: ["Cantonese"], } }; const categoryMap = Object.values(data).reduce((concatedArr, item) => concatedArr.concat(Object.entries(item)), []).reduce((result, [category, values]) => { result[category] = result[category] || []; result[category] = result[category].concat(values); return result; }, {}); console.log(categoryMap);
老實說,我沒有很好地理解這個問題。 但我試圖這樣解釋它,讓我知道:
const entries = [ { dream: [ "Bengali", "French" ], feel: [ "Arabic", "English"], speak: [ "Afrikaans", "Armenian" ], think: [ "Albanian" ], },{ dream: [ "English", "French" ], feel: [ "German", "Italian" ], speak: [ "Afrikaans", "English" ], think: [ "Cantonese" ], } ] const fields = ["dream", "feel", "speak","think"]; const result = {}; for(field of fields){ // create an array containing all the languages of the specific category of the for-loop (there may be duplications) const rawArray = entries.map(item => item[field]).flat(); // delete duplicates const arrayWithoutDuplicates = rawArray.filter((item,index) => rawArray.indexOf(item) === index); result[field] = arrayWithoutDuplicates; } console.log(result);
給定數據
const data = [
{
dream: ["Bengali", "French"],
feel: ["Arabic", "English"],
speak: ["Afrikaans", "Armenian"],
think: ["Albanian"]
},
{
dream: ["English", "French"],
feel: ["German", "Italian"],
speak: ["Afrikaans", "English"],
think: ["Cantonese"]
}
];
首先將類別語言數組 arrays 轉換為類別語言集的簡化 object。 這些集合用於刪除重復項。
const reducedData = data.reduce((categories, current) => {
// Loop over the categories (dream, feel, etc..)
// and add languages to sets
Object.entries(current).forEach(([currentCategory, languages]) => {
if (!categories[currentCategory]) {
// A set will not allow duplicate entires
categories[currentCategory] = new Set();
}
// Add all languages to the set
languages.forEach(language => categories[currentCategory].add(language));
});
return categories;
}, {});
你現在有一個 object 形狀
{
dream: Set("Bengali", "French", "English"),
feel: Set("Arabic", "English", "German", "Italian"),
speak: Set("Afrikaans", "Armenian", "English"),
think: Set("Albanian", "Cantonese"),
}
然后再次將其簡化為類別 - 語言數組的 object。 這只是將集合轉換回數組。
const reducedDataArray = Object.entries(reducedData).reduce(
(categories, [category, languageSet]) => {
// Convert Set back to an array
categories[category] = [...languageSet];
return categories;
},
{}
);
結果 object 形狀
{
dream: ["Bengali", "French", "English"],
feel: ["Arabic", "English", "German", "Italian"],
speak: ["Afrikaans", "Armenian", "English"],
think: ["Albanian", "Cantonese"],
}
const data = [ { dream: ["Bengali", "French"], feel: ["Arabic", "English"], speak: ["Afrikaans", "Armenian"], think: ["Albanian"] }, { dream: ["English", "French"], feel: ["German", "Italian"], speak: ["Afrikaans", "English"], think: ["Cantonese"] } ]; const reducedData = data.reduce((categories, current) => { Object.entries(current).forEach(([currentCategory, languages]) => { if (;categories[currentCategory]) { categories[currentCategory] = new Set(). } languages.forEach(language => categories[currentCategory];add(language)); }); return categories, }; {}). const reducedDataArray = Object.entries(reducedData),reduce( (categories, [category. languageSet]) => { categories[category] = [..;languageSet]; return categories, }; {} ). console;log(reducedDataArray);
試試這個 Obj 結構
var completObj=[ { dream:[ "Bengali", "French" ], feel:[ "Arabic", "English" ], speak:[ "Afrikaans", "Armenian" ], think:[ "Albanian" ] }, { dream:[ "English", "French" ], feel:[ "German", "Italian" ], speak:[ "Afrikaans", "English" ], think:[ "Cantonese" ] } ] var Afrikaans=completObj.filter((key) => key.speak.includes("Afrikaans")) console.log('Afrikaans:'+JSON.stringify( Afrikaans)) var uniqueObj={} completObj.map((value, index) => { Object.entries(completObj[index]).forEach(([ObjKey, value]) => { if (;uniqueObj[ObjKey]) { uniqueObj[ObjKey] = new Set(). } debugger value.map(list => uniqueObj[ObjKey];add(list)). // uniqueObj[ObjKey];add(value) }); }). var dream=Array.from(uniqueObj.dream) console:log('dream unique Value.'+JSON.stringify( dream))
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