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?
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')
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)
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")