javascript 檢查數組是否包含多個具有完全相同屬性的元素

Question

我有一個對象數組：

[
  {
   id: 1,
   sku: 'aaaa'
  },
  {
   id: 2,
   sku: 'bbbb'
  },
  {
   id: 3,
   sku: 'cccc'
  },
  {
   id: 4,
   sku: 'aaaa'
  }
]

如何檢查數組中是否存在多個具有相同sku屬性的元素？

例如：我必須使用具有相同道具sku ('aaaa') 的元素 - 在這種情況下，我需要在其他情況下做一些事情 - 沒有

Answer 1

使用 set 獲取一個包含唯一 sku 的數組並比較長度

var skus = items.map(v=>v.sku);
var uniqueSkus = new Set(skus);
console.log(skus.length === uniqueSkus.size)

Answer 2

您可以使用如下示例代碼：

 var a = [ { id: 1, sku: 'aaaa' }, { id: 2, sku: 'bbbb' }, { id: 3, sku: 'cccc' }, { id: 4, sku: 'aaaa' } ]; var b = {}; a.forEach(el => { if (b[el.sku]) { b[el.sku].count++; } else { b[el.sku] = { id: el.id, count: 1 }; } }); console.log(b);

Answer 3

您可以檢查如下數組 function 'some' 會幫助你

 var arr = [
  {
   id: 1,
   sku: 'aaaa'
  },
  {
   id: 2,
   sku: 'bbbb'
  },
  {
   id: 3,
   sku: 'cccc'
  },
  {
   id: 4,
   sku: 'aaaa'
  }
]

const val = 'aaaa'

const isAvailable = arr.some(function(arrVal) {
        return val === arrVal.sku;
});

//here isAvailable will return true or false

Answer 4

 const a = [ { id: 1, sku: "aaaa" }, { id: 2, sku: "bbbb" }, { id: 3, sku: "cccc" }, { id: 4, sku: "aaaa" } ]; a.reduce((acc, obj)=>{ // looping through each sku & adding them in acc acc.push(obj.sku); // check if current sku already exits in acc. const duplicate = acc.filter(x=>x === obj.sku); if(duplicate.length>1){ // do something or nothing with current obj as similar SKUs are found // i'm adding a new property called x=10 if same SKUs are found. obj.x = 10; }else{ // do something or nothing with current obj as similar SKUs are found // i'm adding a new property called y=10 if not same SKUs. obj.y=10; } return acc; }, []); console.log(a);