这个问题有点老了，但我的选择是

    let finalTab = [{id: 1, name: 'dupont'}, {id: 2, name: 'tintin'}, {id: 3, name:'toto'}]; // Your array of object you want to populate with distinct data
    const tabToCompare = [{id: 1, name: 'dupont'}, {id: 4, name: 'tata'}]; // A array with 1 new data and 1 is contain into finalTab
    
    finalTab.push(
      ...tabToCompare.filter(
        tabToC => !finalTab.find(
          finalT => finalT.id === tabToC.id)
      )
    ); // Just filter the first array, and check if data into tabToCompare is not into finalTab, finally push the result of the filters

    console.log(finalTab); // Output : [{id: 1, name: 'dupont'}, {id: 2, name: 'tintin'}, {id: 3, name: 'toto'}, {id: 4, name: 'tata'}];

someArray = [{a: 'a1 value', b: {c: "c1 value"},
             {a: 'a2 value', b: {c: "c2 value"}]
newObject = {a: 'a2 value', b: {c: "c2 value"}}

//New object which needs check for duplicity

let isExists = checkForExists(newObject) {
    return someArray.some(function(el) {
        return el.a === newObject.a && el.b.c === newObject.b.c;
    });
}
// write your logic here 
// if isExists is true then already object in an array else you can add

我知道这是一个非常老的问题，但如果你使用ES6，你可以使用一个非常小的版本:

[1,2,3].filter(f => f !== 3).concat([3])

非常简单，首先添加一个过滤器，删除项目-如果它已经存在，然后通过concat添加它。

下面是一个更现实的例子:

const myArray = ['hello', 'world']
const newArrayItem

myArray.filter(f => f !== newArrayItem).concat([newArrayItem])

如果你的数组包含对象，你可以像这样调整过滤器函数:

someArray.filter(f => f.some(s => s.id === myId)).concat([{ id: myId }])

推送后删除重复项

如果你已经有一个包含重复项的数组，将对象数组转换为字符串数组，然后使用Set()函数消除重复项:

let arr_obj = [
    { name: "tom", text: "tasty" }, 
    { name: "tom", text: "tasty" }
]

let arr_str = arr_obj.map(JSON.stringify)

let arr_unique = [...new Set(arr_str)].map(JSON.parse) 

推前检查

如果你到目前为止没有重复的元素，你想在推入一个新元素之前检查重复:

let arr_obj = [
    { name: "tom", text: "tasty" },
    { name: "tim", text: "tusty" }
]

let new_obj = { name: "tom", text: "tasty" }

let arr_str = arr_obj.map(JSON.stringify)

!arr_str.includes(JSON.stringify(new_obj)) && arr_obj.push(new_obj)

短的例子:

if (typeof(arr[key]) === "undefined") {
  arr.push(key);
}

使用数组是很容易做到的。函数findIndex，它以函数作为参数:

var arrayObj = [{name:"bull", text: "sour"},
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" }
]
var index = arrayObj.findIndex(x => x.name=="bob"); 
// here you can check specific property for an object whether it exist in your array or not

index === -1 ? arrayObj.push({your_object}) : console.log("object already exists")