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

你可以用一个自定义方法扩展Array原型:

// check if an element exists in array using a comparer function
// comparer : function(currentElement)
Array.prototype.inArray = function(comparer) { 
    for(var i=0; i < this.length; i++) { 
        if(comparer(this[i])) return true; 
    }
    return false; 
}; 

// adds an element to the array if it does not already exist using a comparer 
// function
Array.prototype.pushIfNotExist = function(element, comparer) { 
    if (!this.inArray(comparer)) {
        this.push(element);
    }
}; 

var array = [{ name: "tom", text: "tasty" }];
var element = { name: "tom", text: "tasty" };
array.pushIfNotExist(element, function(e) { 
    return e.name === element.name && e.text === element.text; 
});

其他回答

短的例子:

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

A是你拥有的对象数组

a.findIndex(x => x.property=="WhateverPropertyYouWantToMatch") <0 ? 
a.push(objectYouWantToPush) : console.log("response if object exists");

对于字符串数组(但不是对象数组),你可以通过调用.indexOf()来检查一个项是否存在,如果不存在,则将该项推入数组:

var newItem = "NEW_ITEM_TO_ARRAY"; var array = ["OLD_ITEM_1", "OLD_ITEM_2"]; array.indexOf(newItem) === -1 ?array.push(newItem): console.log("此项已存在"); console.log(数组)

推动动态

var a = [
  {name:"bull", text: "sour"},
  {name: "tom", text: "tasty" },
  {name: "Jerry", text: "tasty" }
]

function addItem(item) {
  var index = a.findIndex(x => x.name == item.name)
  if (index === -1) {
    a.push(item);
  }else {
    console.log("object already exists")
  }
}

var item = {name:"bull", text: "sour"};
addItem(item);

用简单的方法

var item = {name:"bull", text: "sour"};
a.findIndex(x => x.name == item.name) == -1 ? a.push(item) : console.log("object already exists")

如果数组只包含基元类型/简单数组

var b = [1, 7, 8, 4, 3];
var newItem = 6;
b.indexOf(newItem) === -1 && b.push(newItem);

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")