doubt in a program of convert decimal to Hexadecimal-please clarify

[Babu Singh]

Hello,

i am making a program of convert decimal to Hexadecimal. please write what is difference between these programs.

 public class DeciToHexa1
{

public static String Dhexadecimal(int w) 
    {
    	int rem;
    	String output="";
    	String digit;
    	String backwards="";
    	
    	do
    	{    		
    		rem=w%16;
    		digit=DtoHex(rem);
    		w=w/16;
    		output+=digit;
    	}
    	while(w/16!=0);

    	rem=w%16;
    	
    	digit=DtoHex(rem);
    	
    	output=output+digit;

    	for(int i=output.length()-1; i>=0; i--)
    	{
    		backwards+=output.charAt(i);
    	}

    	return backwards;
    }
    
    
    public static String DtoHex(int rem)
    {		
    	
    	String str1=String.valueOf(rem);
    	
    		if(str1.equals("10"))
    			str1="A";
    		
    		else if(str1.equals("11"))
    			str1="B";
    		
    		else if(str1.equals("12"))
    			str1="C";
    		
    		else if(str1.equals("13"))
    			str1="D";
    		
    		else if(str1.equals("14"))
    			str1="E";
    		
    		else if(str1.equals("15"))
    			str1="F";
    		
    		else
    			str1=str1;
   
    	
    	return str1;
    }
public static void main(String[] args)
{
int in=56;
  System.out.println(Dhexadecimal(in));

}
}    

output is: 38

  public class DeciToHexa1
{

public static String Dhexadecimal(int w) 
    {
    	int rem;
    	String output="";
    	String digit;
    	String backwards="";
    	
    	do
    	{    		
    		rem=w%16;
    		digit=DtoHex(rem);
    		w=w/16;
    		output+=digit;
    	}
    	while(w/16!=0);

    	//rem=w%16;
    	
    	//digit=DtoHex(rem);
    	
    	//output=output+digit;

    	for(int i=output.length()-1; i>=0; i--)
    	{
    		backwards+=output.charAt(i);
    	}

    	return backwards;
    }
    
    
    public static String DtoHex(int rem)
    {		
    	
    	String str1=String.valueOf(rem);
    	
    		if(str1.equals("10"))
    			str1="A";
    		
    		else if(str1.equals("11"))
    			str1="B";
    		
    		else if(str1.equals("12"))
    			str1="C";
    		
    		else if(str1.equals("13"))
    			str1="D";
    		
    		else if(str1.equals("14"))
    			str1="E";
    		
    		else if(str1.equals("15"))
    			str1="F";
    		
    		else
    			str1=str1;
   
    	
    	return str1;
    }
public static void main(String[] args)
{
int in=56;
  System.out.println(Dhexadecimal(in));

}
}   

output is: 8

[Henry Wong]

please write what is difference between these programs

In the first case, your do-loop terminates prematurely, and you have code following it that fixes it. In the second case, your do-loop terminates prematurely, and you don't have code following it that fixes it.

IMO, neither case is optimal. Maybe it would be better to fix the do-loop.

do  
{ 
    // blah blah blah             
} while (w != 0);

Henry

[Henry Wong]

Another suggestion, instead of generating the output string backwards -- requiring the for-loop to reverse it back -- maybe it would be better to generate it in a forward direction. Meaning, instead of this...

output+=digit;

How about this...

output = digit + output;

Henry

[Babu Singh]

Dear Sir,

i am asking in first cast output is: 38 and in the second case output is: 8

when i use that code in a loop

  rem=w%16;   
           
        digit=DtoHex(rem);   
           
        output=output+digit;   

why again write thses outside the loop

[Henry Wong]

why again write thses outside the loop

As mentioned, the code outside of the loop is needed because your loop terminated prematurely. It does one more iteration of the loop.

My suggestion is to get rid of that code, and fix the do-loop so that it doesn't terminate prematurely.

Henry

[Babu Singh]

Dear Sir,

thank you for your suggestion.

[Babu Singh]

Dear Sir,

Can you give some light on fix the do-loop so that it doesn't terminate prematurely.

[Henry Wong]

Babu lal wrote:Dear Sir,

Can you give some light on fix the do-loop so that it doesn't terminate prematurely.

I showed you the fix, in my first response (not tested, of course).

Henry

[Babu Singh]

[Babu Singh]

[Babu Singh]

Dear Sir,

Now tested.

   public static String Dhexadecimal(int w) 
    {
    	int rem;
    	String output="";
    	String digit;
    	    	
    	do
    	{    		
    		rem=w%16;
    		digit=DtoHex(rem);
    		w=w/16;
    		output=digit+output;

    	}
    	while(w!=0);
         return output;

    } 

Thanks a lot.