JavaScript study notes (ten) basic packaging types

Only objects have properties and methods, that is, complex data types have properties and methods

The basic wrapper type is to wrap a simple data type into a complex data type

JavaScript provides three special reference types: String, Number, Boolean

        //基本包装类型,就是把简单数据类型包装成了复杂数据类型
        var str = '简单数据类型';
        console.log(str.length);
        //js会把基本数据类型转换成复杂数据类型,相当于:
        // 1.生成临时变量,把简单数据类型包装成复杂数据类型
        // 2.赋值给声明的字符变量
        // 3.销毁临时变量
        var temp = new String('简单数据类型');
        str = temp;
        temp = null;