js数组操作

//创建数组
var fruits = ["Apple", "Banana"];
console.log(fruits.length);

//访问数组元素
var first = fruits[0];
//Apple
var last = fruits[fruits.length -1];
//Banana

//循环访问一个数组
fruits.forEach(function(item, index, array) {
    console.log(item, index)
});
// Apple 0
// Banana 1

//在数组的末尾追加数组
var newLength = fruits.push("Orange");
//["Apple", "Banana", "Orange"]

//删除数组末尾数组
var last = fruits.pop();
//["Apple", "Banana"]

//删除数组第一个元素
var first = fruits.shift();
//["Banana"]

//在数组开头添加元素
var newLength = fruits.unshift('Strawberry');
//["Strawberry", "Banana"]

//得到数组元素的索引
fruits.push("Mango");
var pos = fruits.indexOf("Banana");
//1

//根据数组索引位置删除元素
var removedItem = fruits.splice(pos, 1);

//复制数组
var shallowCopy = fruits.slice();