Question

假设我们有一个对象：

message { 
  diff: { 
    cat: "Tabby"
    name: "Meow Meow"
  }
}

您可以使用hasOwnProperty（）检查重复项并删除重复项吗？示例

for (key in message.diff) {
   //outputs every change when all keys are updated
   if (message.diff.hasOwnProperty(key)){
     this.uniqueArray.push(key); 
   }
}

编辑：我意识到可能会混淆我想要谈论的内容。我有一个函数，它可以监听任何可以更新的表单元素，将输入记录到控制台中。它主要是监听属性名称。它将自身输出到数组，该数组可能包含也可能不包含重复的名称。

如果我们多次更新表单字段，则会变为：

Current Output: ['name', 'name', 'name', 'cat']
Desired Ouput: ['name', 'cat']

Answer 1

检查数组

中是否存在对象键

for (key in message.diff) {
   //outputs every change when all keys are updated
   if (message.diff.hasOwnProperty(key) &&  this.uniqueArray.indexOf(key) == -1){
     this.uniqueArray.push(key); 
   }
}

Answer 2

您可以使用Object.keys()，Array.prototype.filter()，Array.prototype.includes()来检查对象的属性是否为数组元素Array.prototype.push()，展开元素

＆＃13;

var message = { 
  diff: { 
    cat: "Tabby",
    name: "Meow Meow"
  }
}

var arr = ["name", "cat"];

arr.push(...Object.keys(message.diff).filter(function(diff) {return !arr.includes(diff)}));

console.log(arr);

var message = { 
  diff: { 
    lion: "Tabby",
    tiger: "Meow Meow"
  }
}

arr.push(
  ...Object.keys(message.diff)
  .filter(function(diff) {return !arr.includes(diff)}))

console.log(arr);

＆＃13;

使用hasOwnProperty删除重复项

2 个答案: