js数组里面放键值对(js中数组添加元素的方法)
时间：2021-12-07 13:15作者：科蓝技术员
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()
letfruits=["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(…)
varfruits=["Apple","Banana","Mango"];
varmoreFruits=["Orange",...fruits];
console.log(moreFruits);
//Prints["Orange","Apple","Banana","Mango"]
varsomeoMoreFruits=["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。
varfruits=["Apple","Banana","Mango"];
varmoreFruits=["Orange"];
varsomeoMoreFruits=["Guava","Papaya"];
varallFruits=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~
