1.Array.unshift()# J9 N; x% {$ G
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(...)
1 }+ a" i% M* E6 @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()
' x3 u& l: G0 n( [) U9 H( M 我们还可以使用concat()方法在开头连接两个(或更多)数组。5 p- k9 L0 K! u/ u3 x
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"]
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