1.不可改变的原始值
1) Number var a = 123;
2) Boolean var a = true/false;
3) String var a =””; var a = ‘’;
4) undefined var a = undefined; //数值类型,没有定义
5) null var a = null; //占位
2.引用值
Array Object function …date RegExp
3.小练习
1) var a = 10;
var b = a;
a = 20;
document.write(b);
b的值为10;
2) var arr = [1];
var arr1 = arr;
arr.push(2);
document.write(arr1);
arr1的值为[1,2];
3) var arr = [1, 2];
var arr1 = arr;
arr = [1,3];
document.write(arr1);
arr1的值为[1,2];
4.栈内存--先进去后出来
5.堆内存—散列结构,首先在栈内存 存堆内存地址