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[英]How to convert an object to array of multiple objects in javascript
[英]How to convert multiple objects to a single array and count the length of the objects in javascript?
我有這個代碼:
{bloodStores &&
bloodStores.map((store) => {
if (
store.status === "Stock" &&
store.blood_component === "Whole Blood" &&
store.blood_group === "O+"
) {
{
{' display the length of objects '}
}
}
})}
BloodStores是一個包含過多數據的數組。 我循環並通過獲取我想要的特定內容作為上述代碼進行過濾。
過濾后,我得到了我需要的確切內容,並且都是像波紋管代碼這樣的對象:
{
"donor": "caamir yusuf ali",
"hb": "18.13",
"blood_group": "O+",
"blood_component": "Whole Blood",
"unit": "500",
"bag": "K020068931",
"status": "Stock"
},
{
"donor": "zakariye mohamed adan",
"hb": "16.71",
"blood_group": "O+",
"blood_component": "Whole Blood",
"unit": "500",
"bag": "K02059689",
"status": "Stock"
},
{
"donor": "cabdirashid colaad hassan",
"hb": "17.55",
"blood_group": "O+",
"blood_component": "Whole Blood",
"unit": "250",
"bag": "EE559895",
"status": "Stock"
}
如您所見,對象總數為 3,但如何顯示該數字????
您應該事先進行過濾,然后您可以簡單地呈現過濾后的項目或結果數組的長度。 在 jsx 中不需要這樣做:
const availableZeroPositiveWholeBlood = bloodStores.filter(
({status, blood_component, blood_group}) => (
status === "Stock"
&& blood_component === "Whole Blood"
&& blood_group === "O+"
)
)
return <p>{availableZeroPositiveWholeBlood.length}</p>;
您應該首先使用filter方法獲取一個包含您感興趣的對象的新數組,然后使用數組的length屬性。
\\ before you return from your component, filter out the array
const filteredBloodStores = bloodStores.filter(store => (store.status === "Stock"
&& store.blood_component === "Whole Blood"
&& store.blood_group === "O+"));
\\ and in your render, you can get length of that array
filteredBloodStores.length
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