arry篇
var d=['red','green','black']; alert(typeof d); d.length=2
此时的d返回的结果是["red", "green"]会移除了最后一个如果将length属性设置为大于数组橡树的值,则新增的每一项都会取得undefined值
d.length=99 //长度100
返回
["red", "green", "black", undefined × 96];//在后面添加了新项;
What we Think , latest news
var d=['red','green','black']; alert(typeof d); d.length=2
此时的d返回的结果是["red", "green"]会移除了最后一个如果将length属性设置为大于数组橡树的值,则新增的每一项都会取得undefined值
d.length=99 //长度100
返回
["red", "green", "black", undefined × 96];//在后面添加了新项;