实现一个表示电话号码（要求带有区号和号码，如 010－68911205）的 Phone

类，其中某个构造函数的参数应为表示电话号码的字符串。要求实现相应的 set

和 get 函数来分别设置及获取电话号码中的区号（area，如 010）和号码（number，

如 68911205），重写 Object.toString( )函数打印出整个电话号码。（提示：可使用

String.indexOf( )和 String.substring( )等函数）-Implement a said Phone number (with area code and number, such as 010-68911205) Phone

Class, one of the constructor parameters should be said the phone number of the string. Achieve the set requirements

And get functions to set and get the phone number of the area code (area, such as 010) and number (number,

Such as 68911205), rewrite the Object. The toString () function to print out the phone number. (hint: can use

String. The indexOf () and the String. The substring () function)