详解JavaScript数组开头添加元素的3种方法
本篇文章给大家介绍一下JavaScript中将元素添加到数组开头的3种方法。有一定的参考价值,有需要的朋友可以参考一下,希望对大家有所帮助。
今天,我们来一起学习一下如何把元素添加到数组的开头。
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()
方法在开头连接两个(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"]
原文地址:https://codingnconcepts.com/javascript/how-to-add-element-at-beggining-of-javascript-array/
作者:Orkhan Jafarov
译文地址:https://segmentfault.com/a/1190000039129785
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