Array required but (class name) is found

Question

import java.util.Arrays;
import java.util.Scanner;
class MixNumberWithUnit_AM{
   String unit;
   Mix_AM mixNumber;



   public MixNumberWithUnit_AM (String str) {
      String[] abc= parseUnit(str);
      mixNumber= new Mix_AM(abc[0]);
      unit = abc[1];
   }

   public static MixNumberWithUnit_AM position(String str){
         String userInput= str;
         MixNumberWithUnit_AM ft;
         MixNumberWithUnit_AM in;
         int ftpos = userInput.indexOf("ft");
         int inpos = userInput.indexOf("in");
         int appos = userInput.indexOf("'");
         int quotepos = userInput.indexOf("\"");

   if(ftpos !=-1 && inpos !=1){ // This is if both exist
        String ftString= userInput.substring(0,ftpos+2);
        String inString= userInput.substring(ftpos+2);
        ft= new MixNumberWithUnit_AM(ftString);
        in= new MixNumberWithUnit_AM(inString);
        }

   else if(ftpos !=-1 && inpos ==-1){ //if "feet" exist (only have feet)
        ft= new MixNumberWithUnit_AM(userInput);
        in= new MixNumberWithUnit_AM(" ");// intialize to zero inches
        }

    else if(ftpos ==-1 && inpos !=-1){
        ft= new MixNumberWithUnit_AM(" ");
        in= new MixNumberWithUnit_AM(userInput);
        }

   else if(appos !=-1 && quotepos !=-1){
        String ftString= userInput.substring(0,ftpos+1);
        String inString= userInput.substring(ftpos+1);
        ft= new MixNumberWithUnit_AM(ftString);
        in= new MixNumberWithUnit_AM(inString);
        }
   else if(appos !=-1 && quotepos ==-1){
        ft= new MixNumberWithUnit_AM(userInput);
        in= new MixNumberWithUnit_AM(" ");
        }        

   else if (appos ==-1 && quotepos ==-1){
        ft= new MixNumberWithUnit_AM(" ");
        in= new MixNumberWithUnit_AM(userInput);
        }
    }


   public static String[] parseUnit (String userInput){
      String str= userInput.trim(); 
      int len = str.length();
      String s2=str.substring(len-2); //get the last 2 characters
      String p1="",p2="";

      if(s2.equals("in") || s2.equals("ft") ){
         p1=str.substring(0,len-2).trim();
         p2=s2;
      }
      else{
         s2=str.substring(len-1); //get the last 2 characters
         if (s2.equals("'") || s2.equals("\"") ){
            p1=str.substring(0,len-1).trim();
            p2= s2;
         }
         else{
            p1=""; p2=""; System.out.println("error:input w/o units");}
      }//outer if

      String[] rtn={p1,p2};
      return rtn;
   }//parse

   public String displayMixNumberWithUnit() {
      String str=mixNumber.displayMix();
      if(str.equals("0")){
         str="";
      }
      else{
         str= str+unit; 
      }
      return str;
   }//display

      public static String get(){
         Scanner scan = new Scanner (System.in);
         String userInput = scan.nextLine();
         userInput = userInput.trim();
         return (userInput); 
      } //get       


   public static void main(String[] args, String userInput) {
       String userinput=get();
       MixNumberWithUnit_AM m1=position(userInput);
       System.out.println(m1[0].displayMixNumberWithUnit()+m1[1].displayMixNumberWithUnit());

        userInput = get();
       MixNumberWithUnit_AM m2=position(userInput);
      System.out.println(m2[0].displayMixNumberWithUnit()+m2[1].displayMixNumberWithUnit()); 
        }//main

}//class

When ever I compile this code using jGrasp, I get an error with the arrays. I believe I haven't declared my arrays correctly. I don't understand much about how arrays work. Can someone please help me figure it out.

MixNumberWithUnit_AM.java:105: error: array required, but MixNumberWithUnit_AM found
       System.out.println(m1[0].displayMixNumberWithUnit()+m1[1].displayMixNumberWithUnit());
                            ^
MixNumberWithUnit_AM.java:105: error: array required, but MixNumberWithUnit_AM found
       System.out.println(m1[0].displayMixNumberWithUnit()+m1[1].displayMixNumberWithUnit());
                                                             ^
MixNumberWithUnit_AM.java:109: error: array required, but MixNumberWithUnit_AM found
      System.out.println(m2[0].displayMixNumberWithUnit()+m2[1].displayMixNumberWithUnit());
                           ^
MixNumberWithUnit_AM.java:109: error: array required, but MixNumberWithUnit_AM found
      System.out.println(m2[0].displayMixNumberWithUnit()+m2[1].displayMixNumberWithUnit());
                                                            ^
4 errors

You should add the `Java` tag to this question, btw. – Hamza Kubba Oct 14 '13 at 19:34 — Hamza Kubba, Oct 14 '13 at 19:34
Thanks. I forgot to add that. – user2868770 Oct 14 '13 at 19:38 — user2868770, Oct 14 '13 at 19:38

score 3 · Answer 1 · answered Oct 14 '13 at 19:39

3

   MixNumberWithUnit_AM m1=position(userInput);
   System.out.println(m1[0].displayMixNumberWithUnit()+m1[1].displayMixNumberWithUnit());

Variable m1 is not an array. It is an object reference.

answered Oct 14 '13 at 19:39

Jim Garrison

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score 0 · Answer 2 · answered Oct 14 '13 at 19:39

Your position() method has a return type of MixNumberWithUnit_AM. As seen by this line

MixNumberWithUnit_AM m1=position(userInput);

When then try to access the variable m1 you are doing so in the fashion of an array when it is not an array, it is an object of type MixNumberWithUnit_AM in this line

System.out.println(m1[0].displayMixNumberWithUnit()+m1[1].displayMixNumberWithUnit());

If your object MixNumberWithUnit_AM has a field which is an array then you will have to access it like

m1.arrayField[0]....

score 0 · Answer 3 · answered Oct 14 '13 at 19:40

you have declared MixNumberWithUnit_AM position(String str) function to return an object of class MixNumberWithUnit_AM. But in your following code fragment:

   MixNumberWithUnit_AM m1=position(userInput);  // m1 is returned as object, 
                //you are even declaring m1 as object
    System.out.println(m1[0].displayMixNumberWithUnit()+m1[1].displayMixNumberWithUnit());
   // you are accessing it as array

Array required but (class name) is found

3 Answers3