本文已经过原作者 Orkhan Jafarov 授权翻译。
今天，我们来一起学习一下如何把元素添加到元素的首个元素。
1.Array.unshift()
let fruits = ["Apple", "Banana", "Mango"]; fruits.unshift("Orange"); console.log(fruits); // Prints ["Orange", "Apple", "Banana", "Mango"] fruits.unshift("Guava", "Papaya"); console.log(fruits); // Prints ["Guava", "Papaya", "Orange", "Apple", "Banana", "Mango"]
2.使用展开运算符(...)
var fruits = ["Apple", "Banana", "Mango"]; var moreFruits = ["Orange", ...fruits]; console.log(moreFruits); // Prints ["Orange", "Apple", "Banana", "Mango"] var someoMoreFruits = ["Guava", "Papaya", ...moreFruits]; console.log(someoMoreFruits); // Prints ["Guava", "Papaya", "Orange", "Apple", "Banana", "Mango"] console.log(fruits); // Prints ["Apple", "Banana", "Mango"]
3.使用 Array.concat()
我们还可以使用concat() 在开头连接两个(或更多)数组。
var fruits = ["Apple", "Banana", "Mango"]; var moreFruits = ["Orange"]; var someoMoreFruits = ["Guava", "Papaya"]; var allFruits = someoMoreFruits.concat(moreFruits, fruits); console.log(allFruits); // Prints ["Guava", "Papaya", "Orange", "Apple", "Banana", "Mango"]
完~我是小智，我要去刷碗了，我们下期再见~
作者：Orkhan Jafarov 译者：前端小智 来源: dev
原文：https://codingnconcepts.com/javascript/how-to-add-element-at-beggining-of-javascript-array/
