錯誤信息無法找到符號 - 可變mobileserviceprovider

Question

我已成功編譯我的代碼：

/** 
    * to write a simple java class Mobile that models a mobile phone. 
    * 
    * @author (jamal) 
    * @version (20/10/13) 
    */ 
    public class Mobile 

    { 
     // type of phone 
     private String phonetype; 
     // size of screen in inches 
     private int screensize; 
     // menory card capacity 
     private int memorycardcapacity; 
     // name of present service provider 
     private String serviceprovider; 
     // type of contract with service provider 
     private int typeofcontract; 
     // camera resolution in megapixels 
     private int cameraresolution; 
     // the percentage of charge left on the phone 
     private int checkcharge; 
     // wether the phone has GPS or not 
     private String GPS; 
     // instance variables - replace the example below with your own 
     private int x; 

     // The constructor method 

     public Mobile(String mobilephonetype, int mobilescreensize, 
       int mobilememorycardcapacity,int mobilecameraresolution,String mobileGPS, String newserviceprovider) { 
      this.phonetype = mobilephonetype; 
      this.screensize = mobilescreensize; 
      this.memorycardcapacity = mobilememorycardcapacity; 
      this.cameraresolution = mobilecameraresolution; 
      this.GPS = mobileGPS; 

      // you do not use this ones during instantiation,you can remove them if you do not need or assign them some default values 
      //this.serviceprovider = newserviceprovider; 
      //this.typeofcontract = 12; 
      //this.checkcharge = checkcharge; 

     Mobile samsungPhone = new Mobile(
     "Samsung" // String mobilephonetype 
    , 1024 // int mobilescreensize 
    , 2  // int mobilememorycardcapacity 
    , 8  // int mobilecameraresolution 
    , "GPS" //String mobileGPS 
    , "verizon" // String newserviceprovider 
    ); 


      //typeofcontract = 12; 
      //checkcharge = checkcharge; 

     } 

     // A method to display the state of the object to the screen 
     public void displayMobileDetails() { 
      System.out.println("phonetype: " + phonetype); 
      System.out.println("screensize: " + screensize); 
      System.out.println("memorycardcapacity: " + memorycardcapacity); 
      System.out.println("cameraresolution: " + cameraresolution); 
      System.out.println("GPS: " + GPS); 
      System.out.println("serviceprovider: " + serviceprovider); 
      System.out.println("typeofcontract: " + typeofcontract); 
    } 

      /** 
    * The mymobile class implements an application that 
    * simply displays "new Mobile!" to the standard output. 
    */ 
    public class mymobile { 
     public void main(String[] args) { 
      System.out.println("new Mobile!"); //Display the string. 
     } 
    } 
     public static void buildPhones(){ 
     Mobile Samsung = new Mobile("Samsung", 3, 4, 8, "verizon", 
        "GPS"); 
     Mobile Blackberry = new Mobile("Blackberry", 3, 4, 
        8, "verizon", "GPS"); 
    } 
     public static void main(String[] args) { 
      buildPhones(); 
    } 

    } 

然而，當我嘗試添加以下代碼：

//Mutator for newserviceprovider 
    public void setnewserviceprovider(String newserviceprovider) 
    { 
    this.newserviceprovider = newserviceprovider; 
    } 

    //Mutator for contracttype 
    public void setcontracttype(String contracttype) 
    { 
    this.contracttype = contracttype; 
    } 

代碼在上面添加：

/** 
* to write a simple java class Mobile that models a mobile phone. 
* 
* @author (jamal) 
* @version (1/10/13) 
*/ 
public class Mobile 

{ 
    // type of phone 
    private String phonetype; 
    // size of screen in inches 
    private int screensize; 
    // menory card capacity 
    private int memorycardcapacity; 
    // name of present service provider 
    private String mobileServiceProvider; 
    // type of contract with service provider 
    private int typeofcontract; 
    // camera resolution in megapixels 
    private int cameraresolution; 
    // the percentage of charge left on the phone 
    private int checkcharge; 
    // wether the phone has GPS or not 
    private String GPS; 
    // instance variables - replace the example below with your own 
    private int x; 

    // The constructor method 

    public Mobile(String mobilephonetype, int mobilescreensize, 
      int mobilememorycardcapacity, String mobileServiceProvider, int mobilecameraresolution, String mobileGPS) { 
     this.phonetype = mobilephonetype; 
     this.screensize = mobilescreensize; 
     this.memorycardcapacity = mobilememorycardcapacity; 
     this.mobileServiceProvider = mobileServiceProvider; 
     this.cameraresolution = mobilecameraresolution; 
     this.GPS = mobileGPS; 

     // you do not use this ones during instantiation,you can remove them if you do not need or assign them some default values 
     //this.serviceprovider = newserviceprovider; 
     //this.typeofcontract = 12; 
     //this.checkcharge = checkcharge; 

    // Mobile samsungPhone = new Mobile(
// "Samsung" // String mobilephonetype 
//, 1024 // int mobilescreensize 
//, 2  // int mobilememorycardcapacity 
//, 8  // int mobilecameraresolution 
//, "GPS" //String mobileGPS 
//, "verizon" // String newserviceprovider 
//); 


     //typeofcontract = 12; 
     //checkcharge = checkcharge; 

    } 
    //Mutator for newserviceprovider 
    public void setmobileServiceProvider(String mobileServiceProvider) 
    { 
    this.mobileServiceProvider = mobileServiceProvider; 
    } 

    // A method to display the state of the object to the screen 
    public void displayMobileDetails() { 
     System.out.println("phonetype: " + phonetype); 
     System.out.println("screensize: " + screensize); 
     System.out.println("memorycardcapacity: " + memorycardcapacity); 
     System.out.println("cameraresolution: " + cameraresolution); 
     System.out.println("GPS: " + GPS); 
     System.out.println("mobileServiceProvider: " + mobileServiceProvider); 
     System.out.println("typeofcontract: " + typeofcontract); 
} 

     /** 
* The mymobile class implements an application that 
* simply displays "new Mobile!" to the standard output. 
*/ 
public class mymobile { 
    public void main(String[] args) { 
     System.out.println("new Mobile!"); //Display the string. 
    } 
} 
    public static void buildPhones(){ 
    Mobile Samsung = new Mobile("Samsung", 3, 4, 8, "verizon", 
       "GPS"); 
    Mobile Blackberry = new Mobile("Blackberry", 3, 4, 
       8, "verizon", "GPS"); 
} 
    public static void main(String[] args) { 
     buildPhones(); 
} 

} 

我收到錯誤信息找不到符號 - 變量mobileserviceprovider

任何answers.replies和幫助將不勝感激，因爲我真的失去了！

Answer 1

編譯錯誤告訴您在Mobile類中沒有名爲mobileserviceprovider的類實例變量。添加

private String mobileServiceProvider; 

的Java命名慣例表明變量使用駝峯命名變量，例如mobileServiceProvider

讀

• Understanding Instance and Class Members
• Naming Conventions