Actual or formal argument lists differs in length

Question

When I try to put something in the    brackets of Friends f   new Friends friendsName  friendsAge   it comes up with the error       Constructor Friends in class Friends cannot by applied to given types    Required  no arguments  Found  String  int  Reason  actual or formal   argument lists differ in length    But when I take out the arguments my friends list only displays  null 0   Are the values not set even though I have String friendsName   input next      Also  when I try to remove a friend  it doesn t do anything  In the source code it does bring up a warning       Suspicious call to util java Collection remove  Given object cannot   contain given instances of String  expected Friends     I m confused on what that all means   import java util ArrayList  import java util Scanner   public class Friends       public static void main  String   args                 int menu                 int choice          choice   0                 Scanner input   new Scanner System in           ArrayList lt  Friends  gt  friendsList   new ArrayList lt    gt                     System out println   1  Add a Friend             System out println   2  Remove a Friend             System out println   3  Display All Friends             System out println   4  Exit             menu   input nextInt             while menu    4                             switch menu                                                  case 1                   while choice    2                                        System out println  Enter Friend s Name                          String friendsName   input next                        System out println  Enter Friend s Age                          int friendsAge   input nextInt                                                       Friends f   new Friends friendsName  friendsAge                       friendsList add f                       System out println  Enter another  1  Yes  2  No                        choice   input nextInt                      break               case 2                   System out println  Enter Friend s Name to Remove                      friendsList remove input next                                        break                  case 3                   for int i   0  i  lt  friendsList size    i                                          System out println friendsList get i  name         friendsList get i  age                                             break                                     System out println   1  Add a Friend             System out println   2  Remove a Friend             System out println   3  Display All Friends             System out println   4  Exit             menu   input nextInt                System out println  Thank you and goodbye             public String name      public int age           public void setName  String friendsName                 name   friendsName             public void setAge  int friendsAge                 age   friendsAge            public String getName                 return name            public int getAge                 return age

User · Answer

The default constructor has no arguments   You need to specify a constructor       public Friends  String firstName  String age

User · Answer

You try to instantiate an object of the Friends class like this   Friends f   new Friends friendsName  friendsAge     The class does not have a constructor that takes parameters  You should either add the constructor  or create the object using the constructor that does exist and then use the set-methods  For example  instead of the above   Friends f   new Friends    f setName friendsName   f setAge friendsAge

User · Answer

Say you have defined your class like this        Data      AllArgsConstructor staticName    of       private class Pair lt P Q gt             public P first          public Q second          So when you will need to create a new instance  it will need to take the parameters and you will provide it like this as defined in the annotation    Pair lt Integer  String gt  pair   Pair of menuItemId  category     If you define it like this  you will get the error asked for    Pair lt Integer  String gt  pair   new Pair menuItemId  category

[java] "Actual or formal argument lists differs in length"

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