属性取值、赋值点与中括号操作符的区别

属性取值、赋值点与中括号操作符的区别

    1、点操作符: 静态的
    2、中括号操作符: 动态的 book[“….”+author]

var book = null;console.log(typeof(book.name));console.log(typeof(book["name"]));报错：Uncaught TypeError: Cannot read property 'name' of nullvar book = "";console.log(typeof(book.name));//underfinedconsole.log(typeof(book["name"]));//underfinedvar book = {name:""};console.log(typeof(book.name));//stringconsole.log(typeof(book["name"]));//string