Mode

Comments

• 

  David  

  Apr 1, 10:04 AM

  /**
  Basically the idea is to compare each value for an index against
  //all the values of the rest of indexes, so basically staying fixed
  //on one index (i) while iterating through the next (j), an example is

  cont...

      that while i=0  j should have gone from 0 to ar.length, then i=1
      and j would do the same, now  while the iteration is occurring do a 
      comparison for the value and keep track 
      through a 'count' how many times it repeats, additionally as the 
      comparison will take place multiple times we need to know which one 
      repeats most and when it does make that variable the mode.
  
      On this code as the second iterator (j) starts always from 0 it will
      evaluate the value twice, however this shouldn't matter as it shouldn't
      affect the end result, meaning that all values will be treated equally.
  
      My suspicion was that the 'count' wasnt being handled properly, but 
      it works for the other Outputs.
  
      However i still keep getting 4 on the second output rather than 2...
  
      I did read the hint but at least particularly for Me it is not so 
      intuitive, i'm still thing over it.
  
      Code below:
      **/
      int mode=0;
      int count=0;
      int maxCount=count;
  
      for (int i=0;i<=ar.length-1; i++){
  
          for(int j=0; j<=ar.length-1; j++){
  
              if(ar[i]==ar[j]){  
  
                  count++;}
          }//2nd for
  
          if(count>maxCount){
  
              maxCount=count;
              mode=ar[i];}
      }
  
      System.out.println(mode);
  }
  

• 

  David  

  Apr 1, 12:37 PM

  Please update with a second hint with further insight!

• 

  Learneroo  

  Apr 2, 10:59 AM

  @David, it looks like your code needs some fixes. E.g. do you reset count for each number...
  If you want extra support and content, consider membership on learneroo for $25.

• 

  David  

  Apr 3, 4:48 PM

  Admin,

  Thanks much for your prompt answer, i wasn't resetting the counter, now my mind is more aware for that in the future... At the end i ended up thinking inside the box {1 to 5} rather than outside {random amount of numbers} to fit to this exercise....

  Thanks and best regards.

• 

  thales  

  Jul 18, 5:49 PM

  a solution , this was very hard!

  my code

• 

  Bernard Mitchell  

  Jul 28, 2:40 PM

  Can I get another hint on this one I've tried to create another array but I'm not sure about how to keep track of the mode. Thanks

• 

  Learneroo  

  Jul 28, 2:55 PM

  @Bernard, all the grades are integers 1 to 5, any way to keep track of them? A solution would be to create an array of size 6 where the index represents the grade and the value represents that

  cont...

  grade's frequency. E.g. for the example {1,2,3,1}, you would create an array that at the end would be {0,2,1,1,0,0}.

• 

  Bernard Mitchell  

  Jul 28, 4:12 PM

  I thought about this earlier but dismissed it , can you have two loops going at the same time, a loop within a loop is what I mean?

• 

  Learneroo  

  Jul 28, 4:16 PM

  You can have nested loops (one loops inside another), but that's not used in the hinted-to solution, which uses two separate loops. (You can solve it another way if you prefer.)

• 

  Bernard Mitchell  

  Jul 29, 2:25 PM

  So I understand that the zeros in the new array are just empty slots right? I still don't understand how you select the number that repeats the most. So far I've done...

  int [] a= new int [6];
      for(int b=0;b<a.length-1;b++){
          int c=ar[b];
  

• 

  Learneroo  

  Jul 29, 2:36 PM

  Your displayed code above doesn't actually do anything. The goal is to have an array at the end that contains the frequency of each number (1-5) from the original array. You can then go through

  cont...

  your new array to get the maximum number (like in earlier challenges). (See a solution if still stuck.)

• 

  Bernard Mitchell  

  Aug 4, 4:31 PM

  int[] an = new int [6];// an ={0,0,0,0,0,0}
      int c=0;
      int d=ar.length-1; 
      while(c<an.length-1){
          d=d-1;
          if(c!=ar[d]){
              an[c]=0;
          }
  

  cont...

          if(c==ar[d]){
              int m=1;
              m=m+1; 
              an[c]=m;
          }
          if(d==0){
              d=ar.length-1;
              c=c+1;
          }
      }
      System.out.println(an);
  

  I'm trying to see if my new array points to the mode can you tell me why I'm getting number and words when I try to print out the array? I feel like my I wrote my if statements incorrectly. Thanks

• 

  Learneroo  

  Aug 4, 7:38 PM

  Java doesn't provide a built-in method for printing an Array's contents. You can either use an ArrayList of create your own method like this one:

  static void printArray(int[] ar){
    for(int n: ar)
      System.out.print(n+" ");
  }
  

• 

  Bernard Mitchell  

  Aug 5, 4:34 PM

  int[] an = new int [6];// an ={0,0,0,0,0,0}
      int c=0;
      int d=ar.length-1; 
      while(c<an.length-1){
          d=d-1;
          if(c!=ar[d]){
              an[c]=0;
          }
  

  cont...

          else if(c==ar[d]){
              int m=1;
              m=m+1; 
              an[c]=m;
          }
          if(d==0){
              d=ar[ar.length-1];
              c=c+1;
          }
      }
      for(int g: an){
          System.out.print(g+" ");
      }
  

  Two questions...If I have two if statements that are true at the same time how does Java respond to this? Second question since one of my variables is the index of the loop is it affected by an if statement that is within the loop. I've provided my code for reference. And if my questions aren't really relevant to helping me solve this problem, can I get a hint to what I'm doing wrong? Thanks PS my code is only meant to establish an array that will lead me to the mode , not the mode itself.

• 

  Learneroo  

  Aug 6, 9:22 AM

  1. Once Java reaches a true statement in an if-else-if block, it stops checking the remaining else-if statements (they're only checked if the previous statements were false, that's why it says "else if").
  2. Any code inside a while-loop can change the value of any variable, including any code in an if-statement.

  cont...

  The solution can be much simpler. Here's a partial solution with the first part solved which you can complete.

• 

  Bernard Mitchell  

  Aug 6, 3:37 PM

  I understand now, I never would have thought of that , especially not knowing about the +=. Just some feedback I feel like the lessons sometimes jump from do able to extremely hard. I feel like

  cont...

  there should be a moderate group of lessons that prepare the user for problems like this one. Thanks again.

• 

  kerry2021

  Jun 3, 11:11 AM

  what does this error mean?
  Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 5
  at Main.doStuff(Main.java:9)
  at Main.main(Main.java:33)

• 

  Murat Han

  Jul 31, 9:44 AM

  Another solution:
  https://www.learneroo.com/user_answers/1695637983