Find whether a row in 2D array is empty and skip printing it-CodePudding

Is there a statement to check if a row of a 2D array contains an empty element?

This is related to homework. The restrictions are no libraries or lists or hashmaps or anything. I have a 2D string array, for instance {{"a","a","a"},{"b","","b"},{"c","c","c"}}. If I print it without checking anything, and some formatting I would get

I'm supposed to check whether the whole row has something empty and skip it if it is, so the correct output would be

I can check a single string if(data[i][j] != null && !data[i][j].isEmpty()), but is there a statement for rows?

The exception stuff is something else

public class Test {
    
    public static void main(String[] args) {
        String[][] data = {{"a","a","a"},{"b","","b"},{"c","c","c"}};
    
        for (int i=0;i<data.length;i  ){
            System.out.println("                                            ");
            try{
                if(/*row data[i] has no empty elements*/)
                    for (int j=0;j<data[i].length;j  ){
                        System.out.println(data[i][j]);
                    }
                else
                    throw new EmptySpotException("Row(" i "is missing elements, skipping line");
            } catch(EmptySpotException e){
                    System.out.println(e.getMessage());
            }
        }
    }
}

CodePudding user response：

Need to check the full row for empty before printing.(or only blanks)

In order to do in one loop, row_output_string is constructed step by step and is print only is condition is false (skip).

public static void main(String[] args)
{      
    String[][] data = {{"a","a","a"},{"b","","b"},{"c","c","c"}};
    for (int i=0;i<data.length;i  ){
        
        boolean skip=false;
        //only to iterate once
        StringBuffer sb= new StringBuffer();
        try{  
          //check for empty
          for (int j=0;j<data[i].length;j  ){
              if(data[i][j].isBlank())
              {
                  skip=true;
                  throw new Exception("Row[" i "]is missing elements, skipping line");
              }
              sb.append((j!=data[i].length-1) ? data[i][j] "\n" :data[i][j]);
          }
        }
        catch(Exception e){
           //System.out.println("to be comment" e.getMessage());
        };
        
        if(!skip)
        {
          System.out.println("                                            ");
          System.out.println(sb);
        }
    }
}

Note: Considering the termination of try-block when exception arise an enhancement could be:

public static void main(String[] args)
{      
    String[][] data = {{"a","a","a"},{"b","","b"},{"c","c","c"}};
    for (int i=0;i<data.length;i  ){
        //only to iterate once
        StringBuffer sb= new StringBuffer();
        try{  
          //check for empty
          for (int j=0;j<data[i].length;j  ){
              if(data[i][j].isBlank())
              {
                  sb=null;
                  throw new Exception("Row[" i "]is missing elements, skipping line");  
              }
              sb.append((j!=data[i].length-1) ? data[i][j] "\n" :data[i][j]);
          }
        }
        catch(Exception e){
           System.out.println("to be comment" e.getMessage());
        };
          
      if(sb!=null)
      {
          System.out.println("                                            ");
          System.out.println(sb);
      }    
    }
}

CodePudding user response：

Your expected output shows no output from an exception so I am excluding exception handling. You can add that back in where you deem appropriate.

I would recommend using a labelled loop which is a normal part of Java and should meet your requirements.

simply iterate thru the array of arrays as shown.
then check each single array for an empty string.
if the string is empty, continue to the next array via the outer loop
otherwise print the appropriate output.

String[][] data = {{"a","a","a"},{"b","","b"},{"c","c","c"}};
next:
for(String[] arr : data) {
    for(String v : arr) {
        if (v.isEmpty()) {
            // empty element found so skip this array
            continue next;
        }
    }
    System.out.println("                                            ");
    for (String v : arr) {
        System.out.println(v);
    }
}

prints

Note: Just like iterating over an array of SomeType from a single array (e.g. for (SomeType s : arrayOfSomeType) You can also iterate over an array of array of SomeType the same way (for(SomeType[] arr : arrayOfArrayOfSomeType). This can greatly simplify processing "2D" arrays as demonstrated above.