如何检查数组是否包含特定对象[重复]

Question

我正在尝试检查对象数组是否包含特定对象或具有特定属性的对象。

var mainArray = [
{name:"Yahya", age:"29"},
{name:"Ahmed", age:"19"},
{name:"Mohamed", age:"10"},
{name:"Ali", age:"32"},
{name:"Mona", age:"25"},
{name:"Shady", age:"62"},
{name:"Reem", age:"11"},
{name:"Marwa", age:"52"}
]

var myObject = {name:"Yahya", age:"29"};

function check() {
if (mainArray.indexOf(myObject) > -1) {
  console.log("true")
  return true;
} else {
  console.log('false')
  return false;
}
};

<button onClick="check()">Check</button>

然而，这里的对象与数组对象之一相同。但它返回 false 。 我试过包含，也没有工作。

Answer 1

如果您想检查对象数组是否包含该特定对象，则可以使用Array.some

var mainArray = [{
    name: "Yahya",
    age: "29"
  },
  {
    name: "Ahmed",
    age: "19"
  },
  {
    name: "Mohamed",
    age: "10"
  },
  {
    name: "Ali",
    age: "32"
  },
  {
    name: "Mona",
    age: "25"
  },
  {
    name: "Shady",
    age: "62"
  },
  {
    name: "Reem",
    age: "11"
  },
  {
    name: "Marwa",
    age: "52"
  }
]

var myObject = {
  name: "Yahya",
  age: "29"
};

let ans = mainArray.some(function(arrVal) {
  return myObject.name === arrVal.name;
});
console.log(ans)

您也可以使用filter 方法。在这种情况下，它将返回匹配元素的数组。检查返回数组的长度以验证它是否包含所需的元素

var mainArray = [{
    name: "Yahya",
    age: "29"
  },
  {
    name: "Ahmed",
    age: "19"
  },
  {
    name: "Mohamed",
    age: "10"
  },
  {
    name: "Ali",
    age: "32"
  },
  {
    name: "Mona",
    age: "25"
  },
  {
    name: "Shady",
    age: "62"
  },
  {
    name: "Reem",
    age: "11"
  },
  {
    name: "Marwa",
    age: "52"
  }
]

var myObject = {
  name: "Yahya",
  age: "29"
};

let newAns = mainArray.filter(function(item) {
  return item.name === myObject.name && item.age === myObject.age
})
if (newAns.length > 0) {
  console.log(true);
} else {
  console.log(false)
}

Answer 2

findIndex 给出了一个Array 方法，我们可以像下面这样简单地做一些事情

var mainArray = [
  {name:"Yahya", age:"29"},
  {name:"Ahmed", age:"19"},
  {name:"Mohamed", age:"10"},
  {name:"Ali", age:"32"},
  {name:"Mona", age:"25"},
  {name:"Shady", age:"62"},
  {name:"Reem", age:"11"},
  {name:"Marwa", age:"52"}
]

var myObject = {name:"Yahya", age:"29"};

function check() {
  if (mainArray.findIndex(obj => obj.name == myObject.name && obj.age == myObject.age) > -1) {
    console.log("true")
    return true;
  } else {
    console.log('false')
    return false;
  }
};

<button onClick="check()">Check</button>

Answer 3

您可以检查该数组的some 元素是否与您在字符串化时检查的对象相同，如下所示：

mainArray.some(e => JSON.stringify(e) === JSON.stringify(myObject))

function check() {
 console.log(mainArray.some(e => JSON.stringify(e) === JSON.stringify(myObject)))
};


let mainArray = [{
    name: "Yahya",
    age: "29"
  },
  {
    name: "Ahmed",
    age: "19"
  },
  {
    name: "Mohamed",
    age: "10"
  },
  {
    name: "Ali",
    age: "32"
  },
  {
    name: "Mona",
    age: "25"
  },
  {
    name: "Shady",
    age: "62"
  },
  {
    name: "Reem",
    age: "11"
  },
  {
    name: "Marwa",
    age: "52"
  }
]

let myObject = {
  name: "Yahya",
  age: "29"
};

<button onClick="check()">Check myObject</button>

Answer 4

indexOf 将尝试使用基本比较机制在集合中查找对象。尝试运行： {name:"Yahya", age:"29"} === {name:"Yahya", age:"29"} 在 javascript 控制台中，你会得到错误，因为它们是 2 个不同的对象，使用相同的字符串文字创建。

我认为您应该阅读更多关于 OOP 中对象的信息。

要使用 Array.prototype.some() 提供的测试器函数检查集合是否包含元素：

var mainArray = [
    {name:"Yahya", age:"29"},
    {name:"Ahmed", age:"19"},
    {name:"Mohamed", age:"10"},
    {name:"Ali", age:"32"},
    {name:"Mona", age:"25"},
    {name:"Shady", age:"62"},
    {name:"Reem", age:"11"},
    {name:"Marwa", age:"52"}
];

var myObject = {name: "Yahya", age: "29"};

function check(object) {
    return mainArray.some(function(element) {
        return element.name === object.name && element.age === object.age;
    })
}

console.log(check(myObject));

请注意，比较是使用“===”完成的，如果您在 mainArray 集合中将年龄设置为字符串并且在 myObject - 作为数字，请改用“==”进行年龄比较。