How to check a boolean method return value in java

java class return boolean

13,315

Solution 1

You can try like this:

if (someObject.doSomething()) //So if your function returns true then the below statement will be executed
{ 
   // print a statment
}
else //This will check for the false condition of your function
{
   // print a different statement           
}

Solution 2

You can try something like this:

if(someObject.doSomething()){
    System.out.print("foo1");
}

else{
    System.out.print("foo2");
}

13,315

Michael N

Updated on May 25, 2022

Comments

Michael N almost 2 years

I am pretty new to Java what I am trying to do may seem really strange but it is a matter of me understanding a little bit about how Java works more than actually accomplishing a set result.

If I have a boolean method for instance:

public class doThings
{

    // imagine the intial value of this variable is set
    // and or modified using getters and setters between the declaration
    // and the following method
    private boolean boolVar;


    public boolean doSomething()
    {
        if(boolVar == true)
        {
            //does things and then returns true
            return true;
        }
        else
        {
            return false;
        }
    }
}

And I want to call this method in another class like so...

public class testDoThings
{

    doThings someObject = new doThings;
    public static void main(String[] args)
    { 
        someObject.doSomething()
    }
}

How do I check (in the class testDoThings) to see if the method has returned true or returned false and print messages accordingly something like this...

public class testDoThings
{

    doThings someObject = new doThings;
    public static void main(String[] args)
    {

        someObject.doSomething()
        if (doSomething() returns true) // yes I am aware this is not
                                        //valid
        { 
            // print a statment
        }
        else if (doSomething() returns false) // yes once again not valid
        {
            // print a different statement           
        }
    }
}

I am aware that you could put these messages in the class containing the method but if I want different messages depending on where the method is called and what it is a called on then putting things in the original class method is not always going to work.

If I am completely off the track here please let me know, if someone can explain this to me though, that would be great!

Daniel Z. almost 8 years

Which would be the same as if(someObject.doSomething() == true){ }else{ }. For more operators check out this site: link
Aakash almost 8 years

Why do you need an "else..if"? Since the condition (method call) is boolean, a simple else would suffice. Also, you don't, probably, want to call the same method twice, just to check the return.
Scary Wombat almost 8 years

This is potentially bad as it may cause doSomething to actually be executed twice.
mhyst almost 8 years

I agree. to both comments. I am professional coder. I just tried to fill the holes. All can be improved. Let me fix it.
mhyst almost 8 years

I don't understand how can people downvote the more explanatory and the best understandable for newbies in here. But hey, that's OK. Downvote if you fell like it.
Daniel Z. almost 8 years

They propably downvoted it before you edited your post. But anyway, as for now, youre code still wouldnt compile, because you have to wrap it in a method. If you fix it and also your comments youll get an upvote.
mhyst almost 8 years

Ok, I did. I hope people don't get mad at me.