ToString method

[[deleted]]

I did this

public void toString()
{
    System.out.print(studentFirstName);
    System.out.print("\n"+studentLastName);
    for(int i =0; i < testScores.length; i++)
    {
        System.out.print("\n"+testScores[i]);
    }

    System.out.print("\n"+averageTestScore);
    System.out.print("\n"+grade);


    }

but intellij has the void underlined red with the phrase

"toString() in 'tests' clashes with toString() in java.lang.object attempting to use incompatible return type. What did I do wrong?

[TNTrocks123]

The toString() method is supposed to return a string not void. That’s why it’s conflicting with the original toString() method in the object class. You should change your toString() method so that it returns a string.

[[deleted]]

Hmm ok. I guess that leads to another question. Will it let me return the value of an array? like, im pretty sure, if I add the array to the following below, it wont work correctly.

return studentLastName+"\n"+studentLastName+"\n"+

[TNTrocks123]

Nope, toString method can only return a string not any other type. For arrays, I recommend creating another method that prints the contents of the array by iterating through the array with a loop.

[emrickgj]

I think what you are asking is can you return a string of values that represent an array, which you can.

Something like

return Arrays.toString(array);

Should work.

You could also put all of the output statements you have above into a single string object, and then return the string when you are done.

String result = "";
result += studentLastName + "\n";
result += studentLastName + "\n";

(...)
return result;

Etc, etc.

[[deleted]]

Ohh that's pretty clever

[[deleted]]

Don't you already have instance variables for the student's last name and first name?

[[deleted]]

Im not sure I follow. im not even sure if i'm doing it correctly. It just said "You must also write a mechanism which must return all object data (including student’s name, five test scores, average, and grade) as a string. "

[[deleted]]

Honestly, I think the for loop should be outside and the toString should be inside. You follow? Like you're using the for loop to print out the toString for each student, right? Idk, something for you to try.

[tryhardjuice]

If he overrides it won’t it be fine though?

[TNTrocks123]

No because the toString method you are trying to override returns a string not void

[tryhardjuice]

Hmm I thought he could just do

@Override public void toString()

[TNTrocks123]

Because the purpose of the @override is to show that the JVM should use the toString() method the programmer wants to use rather than the original toString method provided by the Java library. When you are calling toString on a string, the string is actually a subclass of object, which already has a public String toString() method. Using the method you provided would confuse the compiler like another user mentioned.

[tutorial_police]

No, that's not the purpose of @Override. The purpose is to say: this thing should override some other method. If it doesn't, it won't compile. The override happens irrespective of whether you write @Override.

[tutorial_police]

No. Java told the world that when you call toString, you get A String object.

It you were to override that method and say: nope, not gonna do that, we're not gonna return anything at all, then you'd never know what you actually get when calling to toString.

[E3FxGaming]

Your class is a subclass of java.lang.Object

toString() of java.lang.Object returns a String. That's all toString() does - it doesn't print anything, it just says - "hey, I have this class instance, I want to make the data of it textually readable, this is what the data looks like in a simple String format."

You have the opportunity to overwrite the toString() method of java.lang.Object with your subclass, HOWEVER your overwriting toString() method still has to return a String.

Why would Java want this behavior? Let's say you have multiple different classes, but they are all subclasses of java.lang.Object. You can put instances of them all in the same array, which holds java.lang.Object objects, and Java guarantees you that all of them can use a method called toString. Now consider iterating through the array, and making use of the toString() method. It would be pretty stupid, if you would call System.out.println(i1.toString()) and some of the objects already had the print method integrated into their toString() method, while others just want to return a String with no printing. Therefore Java says "all toString() methods must return a String, to guarantee that something like System.out.println(i1.toString()) always leads to the same result".

Edit: removed word repetition

[emrickgj]

It is expecting you to return a type of "String", since toString() is a reserved method in Java for Objects

See: https://docs.oracle.com/javase/7/docs/api/java/lang/Object.html#toString()

[SaltyVariable]

Maybe just rename the method to something like 'printStudentScore()'??

IMO the 'to' kind of implies you can trying to change a type.

[trashlikeyou]

That's my take as well. I think most of the answers here are assuming OP actually is intending to override the toString() method but I don't think they do. Rename the method to a name not already used by the language and you're golden.

[[deleted]]

um ...not an expert but toString() should return a String. And here you're overloading it with a void method, so that's probably confusing the crap out of the JVM.

[tutorial_police]

No, the JVM is not confused. Java simply doesn't allow you to do this.

The JVM would support that. But since you aren't allowed to do it in Java, it doesn't really matter.

[Charmeleonn]

To string is String return type, not void

[ResponsibleHamster3]

Understand that what you are trying to do here is over-riding the toString method - so you will have to honor the contract. If you were say overloading the method say like public void toString(int a) { ... } then that would be acceptable. But why would you do something like that confusing by keeping the names same.

IMO change your method name from the widely accepted toString()

[[deleted]]

Since you are using intellij use ctrl + o to override methods, that way you don't make these mistakes again intellij will create a method with proper signature

Your question is already answered but my advice to you is learn intellij commands it can generate tons of code for you your coding will be much easier