if loop inside for loop problem

[sahana mithra]

public class ifinsidefor {
public static void main(String[] args){
	String a[]={"cloud","tiger","lion"};
	String value="cloud";
	for(int i=0;i<a.length;i++){
		if(value.equals(a[i])){
			System.out.println("exists");
		}
		else{
			System.out.println("Not in the option");
		}
	}
}
}

This produces the output as follows

exists
Not in the option
Not in the option

I want to restrict this code with the correct output
Please help me
Thanks in advance

[Vijitha Kumara]

Hint: Using a break; statement in a loop causes the loop (inner most loop if you have more than one) to terminate and jump out of it.

[Rudradutt Joshi]

Vijitha Kumara wrote:Hint: Using a break; statement in a loop causes the loop (inner most loop if you have more than one) to terminate and jump out of it.

Also labels are available in java to tell JVM to get out of which loop.

[sahana mithra]

Hi,
I tried giving break

if(value.equals(a[i])){
			System.out.println("exists");
			break;
		}

In the above case if i want to check if lion exists it prints

 Not in the option
Not in the option
exists

In this case i guess break will not help.

[Darryl Burke]

Most importantly here, an if statement or if block is not a loop.

[Suresh Sajja]

you can move "If.. else.." block out of "for" loop.
break the "for" loop when your condition is met.

[Darryl Burke]

Maybe I'm just dense, but I don't see why you're printing something in the else {...} block if you don't want it to be printed.

[Rudradutt Joshi]

Why don't you try like

folLoopLabel : for(int i=0;i<a.length;i++){  
         if(value.equals(a[i])){  
             System.out.println("exists");  
               break folLoopLabel;
         }  
         else{  
             System.out.println("Not in the option");  
         }  
     }  

>

[Campbell Ritchie]

Rudradutt Joshi wrote:Why don't you try like

folLoopLabel : for(int i=0;i<a.length;i++){  
         if(value.equals(a[i])){  
             System.out.println("exists");  
               break folLoopLabel;
         } 
         else{  
             System.out.println("Not in the option");  
         }  
     }  

>

. . . because there is only one thing worse than break; and that is labelled break;.

I know a lot of people will disagree with me here. You have already been given correct solutions, by Darryl Burke and Suresh Sajja.

If you want to do something in that loop, you need a flag, and this is how you can do a linear search

boolean found = false;
for (int i = 0; !found && i < myArray.length; i++)
{
   found = myArray[i].equals(...);
}
System.out.println(found ? "Found" : "Not in  this array");

Remember you can have problems if you pass null or the array contains a null There are ways round that problem.

[Rudradutt Joshi]

A cleanly written code is as much as readable as it is with or without a break,continue or equivalent.

But I like the way Campbell has given and I would try using that one now onwards.

[sahana mithra]

hi ,
Thanks a lot Ritchie for letting me know a nice solution.

I also thank others for helping me with this doubt.

[fred rosenberger]

Just to be a pain...

There is no such thing as an "if loop". It is an if condition or if statement.

[Sean Clark]

Campbell,

That is a really nice clean solution and something that is really simple but which is so easily overlooked, thanks for the example and +1

Sean

[Campbell Ritchie]

You're welcome

Have you worked out what to do about nulls yet?

And of course you can use an int instead of the boolean

int index = -1;
for (int i = 0; index < 0 && i < myArray.length; i++)
{
   if (myArray[i].equals(...))
   {
      index = i;
   }
}
System.out.println(index >= 0 ? "Found at " + index : "Not in  this array");

That allows you to return the index, which is how linear searches usually work. You get index if found and -1 otherwise