在JavaScript中使用删除运算符

Question

After deleting an object property using delete objec.prop3[1] , null is getting replaced in that object property's place.

for ex:

objec: {
  prop1: "aa",
  prop2: "bb",
  prop3: [{
    item1: "i1",
    item2: "i2"
  }, {
    item1: "i3",
    item2: "i4"
  }]
}
for deleting {
  item1: "i3",
  item2: "i4"
}

i am using

for (i = 0; i < objec.prop3.length; i++) {
  if (objec.prop3[i].item2 == "i4") {
    delete object.prop3[i]
  }
}
obtained output:
  objec: {
    prop1: "aa",
    prop2: "bb",
    prop3: [{
        item1: "i1",
        item2: "i2"
      },
      null
    ]
  }
required output:
  objec: {
    prop1: "aa",
    prop2: "bb",
    prop3: [{
      item1: "i1",
      item2: "i2"
    }]
  }

Answer 1

You are trying to delete an element from a array and not a key value pair, to do that you can not use delete instead use some method to delete an element from array..

for (i = 0; i < objec.prop3.length; i++) {
  if (objec.prop3[i].item2 == "i4") {
    object.prop3.splice(i, 1);
  }
}

The splice() method adds/removes items to/from an array, and returns the removed item(s).

Note: This method changes the original array.

array.splice(index,howmany,item1,.....,itemX)

index: Required. An integer that specifies at what position to add/remove items, Use negative values to specify the position from the end of the array

howmany: Required. The number of items to be removed. If set to 0, no items will be removed

item1, ..., itemX: Optional. The new item(s) to be added to the array