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
如果不在列表中，则添加
对于一个简单值的列表，它是一行程序…
[...new Set([...someArray, someElement])]
JavaScript的用法:
var myArray = ['bill','bob']
var alreadyIn = [...new Set([...myArray, 'bob'])] // ['bill','bob']
var notAlreadyIn = [...new Set([...myArray, 'peter'])] // ['bill','bob','peter']
TypeScript文本(注意include vs includes):
interface Array<T> {
include(element: T): Array<T>
}
Array.prototype.include = function (element: any): any[] {
return [...new Set([...this, obj])]
}
.．.但对于对象来说，情况就复杂多了
[...new Set([...someArray.map((o) => JSON.stringify(o)),
JSON.stringify(someElement)]).map((o) => JSON.parse(o))
TypeScript文本处理任何事情:
Array.prototype.include = function (element: any): any[] {
if (element && typeof element === 'object')
return [
...new Set([
...this.map((o) => JSON.stringify(o)),
JSON.stringify(element),
]),
].map((o) => JSON.parse(o))
else return [...new Set([...this, element])]
}
其他回答
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")
短的例子:
if (typeof(arr[key]) === "undefined") {
arr.push(key);
}
如果不在列表中，则添加
对于一个简单值的列表，它是一行程序…
[...new Set([...someArray, someElement])]
JavaScript的用法:
var myArray = ['bill','bob']
var alreadyIn = [...new Set([...myArray, 'bob'])] // ['bill','bob']
var notAlreadyIn = [...new Set([...myArray, 'peter'])] // ['bill','bob','peter']
TypeScript文本(注意include vs includes):
interface Array<T> {
include(element: T): Array<T>
}
Array.prototype.include = function (element: any): any[] {
return [...new Set([...this, obj])]
}
.．.但对于对象来说，情况就复杂多了
[...new Set([...someArray.map((o) => JSON.stringify(o)),
JSON.stringify(someElement)]).map((o) => JSON.parse(o))
TypeScript文本处理任何事情:
Array.prototype.include = function (element: any): any[] {
if (element && typeof element === 'object')
return [
...new Set([
...this.map((o) => JSON.stringify(o)),
JSON.stringify(element),
]),
].map((o) => JSON.parse(o))
else return [...new Set([...this, element])]
}
我更喜欢使用原生js Array.prototype.some()，即使在jqenv中 文档:w3s some or mdn some
let arr = [
{ name: "tom", text: "tasty" },
{ name: "tom", text: "tasty" }
];
let oneMore = { name: "tom", text: "tasty" };
!arr.some(i => i.name == oneMore.name && i.text == oneMore.text)
&& arr.push(oneMore);
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]
