具有唯一值的過濾器陣列-有解無憂

這已經一次又一次地發布，在閱讀完所有內容后，我仍然不知道我做錯了什么。我知道有很多方法可以做到這一點，我覺得我把它們混在一起了。

我試圖從 serviceType 中獲取唯一值，所以我應該只擁有 Cars No，Vans Now，而不是擁有 Cars Now、Cars Now、Vans Now。

見附件代碼

const preFilteredRows = [
{
"serviceType": "Cars Now",
"applictionType": "Direct",
"wheelType": "4x4"
},
{
"serviceType": "Cars Now",
"applictionType": "web",
"wheelType": "2x4"
},
,
{
"serviceType": "Vans Now",
"applictionType": "Direct",
"wheelType": "2x4"
}
]

let tempArr = [];
preFilteredRows.forEach(row => {
    if(row.values[serviceType].length == 1) tempArr.push(row.values[serviceType][0])
})
/* return [...new Set(tempArr)] */
newServiceSet = [...new Set(tempArr)]
console.log(newServiceSet)

更新：非常感謝大家的反饋，非常感謝您對我學習的幫助。

我忘記添加到我的問題中并且剛剛意識到的一部分是，我不僅需要唯一值，而且還需要像下圖那樣顯示它們，因此每個值都有一個值和一個標簽。我不再需要計數了。

具有唯一值的過濾器陣列

uj5u.com熱心網友回復：

如果我理解正確你想要

[
  "Cars Now",
  "Vans Now"
]

做一個映射和過濾，然后做你的傳播運算子以獲得唯一值。

const preFilteredRows = [
{
"serviceType": "Cars Now",
"applictionType": "Direct",
"wheelType": "4x4"
},
{
"serviceType": "Cars Now",
"applictionType": "web",
"wheelType": "2x4"
},
,
{
"serviceType": "Vans Now",
"applictionType": "Direct",
"wheelType": "2x4"
}
]

let tempArr = preFilteredRows.map(row => row.serviceType) // map extracts the serviceType
           .filter(service => service); // filter removes any undefined/empty values

newServiceSet = [...new Set(tempArr)] // only keeps unique values

console.log(newServiceSet)

uj5u.com熱心網友回復：

你可以這樣做：

map- 將每個物件從陣列映射到其serviceType屬性值
new Set- 從上述步驟中生成的陣列中獲取所有唯一值

const preFilteredRows = [
  { "serviceType": "Cars Now", "applictionType": "Direct", "wheelType": "4x4" },
  { "serviceType": "Cars Now", "applictionType": "web", "wheelType": "2x4" },
  { "serviceType": "Vans Now", "applictionType": "Direct", "wheelType": "2x4" }
];

const unique_types = [...new Set(preFilteredRows.map(item => item.serviceType))];
console.log(unique_types);

uj5u.com熱心網友回復：

地圖和過濾器的混合將完成這項作業。

const preFilteredRows = [
{
"serviceType": "Cars Now",
"applictionType": "Direct",
"wheelType": "4x4"
},
{
"serviceType": "Cars Now",
"applictionType": "web",
"wheelType": "2x4"
},
,
{
"serviceType": "Vans Now",
"applictionType": "Direct",
"wheelType": "2x4"
}
]
const n = [...new Set( preFilteredRows.map(obj => obj.serviceType)) ].filter(f => f);

console.log(n)

轉載請註明出處，本文鏈接：https://www.uj5u.com/qiye/448635.html

標籤：javascript

上一篇：如何在js中將點替換為逗號和逗號替換為點

下一篇：ReactJS-未定義的變數