如果两个值都不存在,我如何推入数组?这是我的数组:

[
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" },
    { name: "tom", text: "tasty" }
]

如果我试图再次推入数组的名字:“tom”或文本:“tasty”,我不希望发生任何事情…但如果这两个都不存在那么我就输入。push()

我该怎么做呢?


当前回答

您可以使用foreach检查数组,然后弹出项目,如果它存在,否则添加新的项目…

newItemValue &submitFields是键值对

> //submitFields existing array
>      angular.forEach(submitFields, function(item) {
>                   index++; //newItemValue new key,value to check
>                     if (newItemValue == item.value) {
>                       submitFields.splice(index-1,1);
>                         
>                     } });

                submitFields.push({"field":field,"value":value});

其他回答

我有这个问题,我做了一个简单的原型,使用它,如果你喜欢它

Array.prototype.findOrPush = function(predicate, fallbackVal) {
    let item = this.find(predicate)
    if(!item){
        item = fallbackVal
        this.push(item)
    }
    return item
}

let arr = [{id: 1}]
let item = arr.findOrPush(e => e.id == 2, {id: 2})
console.log(item) // {id: 2} 

// will not push and just return existing value
arr.findOrPush(e => e.id == 2, {id: 2}) 
conslog.log(arr)  // [{id: 1}, {id: 2}]

如果你的项目包含lodash,使用unionBy方法会很简单

import {unionBy} from "lodash";

let arrayObj = [
    { name: "jhon", text: "guitar"},
    { name: "paul", text: "bass" },
    { name: "george", text: "guitar" }
];

// this object will be added to the array
arrayObj = unionBy(arrayObj, [{name: 'ringo', text: 'drums'}], 'name')

// this object will be ignored because already exists  
arrayObj = unionBy(arrayObj, [{name: "jhon", text: "guitar"}], 'name')

这是一个对象比较的工作函数。在某些情况下,您可能需要比较许多字段。 只需循环数组并使用现有项和新项调用此函数。

 var objectsEqual = function (object1, object2) {
        if(!object1 || !object2)
            return false;
        var result = true;
        var arrayObj1 = _.keys(object1);
        var currentKey = "";
        for (var i = 0; i < arrayObj1.length; i++) {
            currentKey = arrayObj1[i];
            if (object1[currentKey] !== null && object2[currentKey] !== null)
                if (!_.has(object2, currentKey) ||
                    !_.isEqual(object1[currentKey].toUpperCase(), object2[currentKey].toUpperCase()))
                    return false;
        }
        return result;
    };

正是出于这些原因,使用像underscore.js这样的js库。union:计算传入数组的并集:在一个或多个数组中出现的唯一项的列表。

_.union([1, 2, 3], [101, 2, 1, 10], [2, 1]);
=> [1, 2, 3, 101, 10]

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")