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()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"]
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/