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
这里你有一种方法可以在一行中为两个数组做这件事:
const startArray = [1,2,3,4]
const newArray = [4,5,6]
const result = [...startArray, ...newArray.filter(a => !startArray.includes(a))]
console.log(result);
//Result: [1,2,3,4,5,6]
其他回答
不确定速度，但stringification + indexOf是一个简单的方法。首先将数组转换为字符串:
let strMyArray = JSON.stringify(myArray);
然后，对于一系列属性-值对，您可以使用:
if (strMyArray.indexOf('"name":"tom"') === -1 && strMyArray.indexOf('"text":"tasty"') === -1) {
myArray.push({ name: "tom", text: "tasty" });
}
查找整个对象更简单:
if (strMyArray.indexOf(JSON.stringify(objAddMe) === -1) {
myArray.push(objAddMe);
}
当你希望通过对象的特定属性进行搜索时，我使用了map和reduce来做到这一点，因为直接进行对象相等通常会失败。
var newItem = {'unique_id': 123};
var searchList = [{'unique_id' : 123}, {'unique_id' : 456}];
hasDuplicate = searchList
.map(function(e){return e.unique_id== newItem.unique_id})
.reduce(function(pre, cur) {return pre || cur});
if (hasDuplicate) {
searchList.push(newItem);
} else {
console.log("Duplicate Item");
}
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'}];
这里你有一种方法可以在一行中为两个数组做这件事:
const startArray = [1,2,3,4]
const newArray = [4,5,6]
const result = [...startArray, ...newArray.filter(a => !startArray.includes(a))]
console.log(result);
//Result: [1,2,3,4,5,6]
我的选择是使用.includes()扩展数组。正如@Darrin Dimitrov所建议的原型:
Array.prototype.pushIfNotIncluded = function (element) {
if (!this.includes(element)) {
this.push(element);
}
}
记住include来自es6，在IE上不起作用: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/includes
