前端工作总结114-JS-JS创建数组的三种方法

隐式创建

var arr=["Audi","BMW","Volvo"];

直接实例化

var arr=new Array("Audi","BMW","Volvo");

创建数组并给数组元素赋值

var arr=new Array();
     arr[0]="Audi";
     arr[1]="BMW";
     arr[2]="Volvo";

注意：

console.log(arr.length); //3
     arr[4]='jeep';
     console.log(arr.length); //5
     console.log(arr[3]); //undefined