How to return statement in java method?

Declare your String k outside try block

public static String j(){
    String k="";
    try{
        k ="10";
        System.out.println(k);
    }
     catch (Exception ignore) {}
    return k; 
}

You need to declare the String variable in the method scope like:

public static String j(){
   String k = "";
   try{
       k ="10";
       System.out.println(k);
    } catch (Exception ignore) {}

    return k;
}

try{
    String k ="10"; // k declare inside the try and it will visible inside try
    System.out.println(k);
    }

 catch (Exception ignore) {}

 return k; // error: cannot find symbol // k not visible out side the try

}

You can try this way

String k ="";
try{  
 k="10";
 System.out.println(k);
} catch (Exception ignore) {}

 return k; 
}

This is because you define String k in try block so it will be local variable cannot be access outside this block

and in the second code you wrote return statement in try block and there is no another one on catch so you got this error : "missing return statement"

so the true code need to be like this :

public static String j(){ 
   String k ="10";
   try{
     System.out.println(k);
     }
   catch (Exception ignore) {}

return k; 
 }

The problem is because k is not defined outside try and catch. Thats why its only working if you return in the try block if you also return null at the bottom that will be the return value of it cant return in the try block.

Do this instead and it'll work:

 public static String j(){
  String k = "";

  try{
     k ="10";
     System.out.println(k);
     }

  catch (Exception ignore) {}

  return k;

}

Define like below, In First case, your local variable k type of String has a scope withing the try block

public static String j(){
 String k ="10";
 try{
    System.out.println(k);
    }

 catch (Exception ignore) {}

 return k;    
}

In second case, You haven't return anything, if an Exception caught. You either rethrow the Exception, or return something meaninfully.

On your fist try, k in the return statement is out of the scope where it is defined (inside the try block).

On your second try, not all code paths in your method returns a value. Your best bet is define k outside the try statement and return it at the end.

public static String j(){
    String k ="10";

     try {
        System.out.println(k);
    }    
    catch (Exception ignore) {}
    return k;     
}

This is because k is not defined in the scope of the return line. You can change it like this:

public static String j(){ //
    String k = "10";
    try {
      System.out.println(k);
    } catch (Exception ignore) {}
    return k; 
}

If your string assignment should be within the try block, give it some default value during declaration (I would recommend null) and then reassign it in the try block.

According to your code the method returns a value of type String.

public static String j(){ 

You have to ensure that the return value is known for each possible execution path. If everything is ok (try-block completed w/o error), k is returned. But in case of a failure (catch-block is executed) the return value for the method is undefined, because there is no specification of the value in or after the catch-block.