Is there an alternative to hyper-indented code?

Question

I often run into code that has to perform lots of checks and ends up being indented at least five or six levels before really doing anything. I am wondering what alternatives exist.

Below I've posted an example of what I'm talking about (which isn't actual production code, just something I came up with off the top of my head).

public String myFunc(SomeClass input)
{
    Object output = null;

    if(input != null)
    {
        SomeClass2 obj2 = input.getSomeClass2();
        if(obj2 != null)
        {
            SomeClass3 obj3 = obj2.getSomeClass3();
            if(obj3 != null && !BAD_OBJECT.equals(obj3.getSomeProperty()))
            {
                SomeClass4 = obj3.getSomeClass4();
                if(obj4 != null)
                {
                    int myVal = obj4.getSomeValue();
                    if(BAD_VALUE != myVal)
                    {
                        String message = this.getMessage(myVal);
                        if(MIN_VALUE <= message.length() &&
                           message.length() <= MAX_VALUE)
                        {
                            //now actually do stuff!
                            message = result_of_stuff_actually_done;
                        }
                    }
                }
            }
        }
    }
    return output;
}

Answer 1

if it's just a readability issue you could make it clearer by moving the nesting to another method. Additionally convert to guard style if you like.

public String myFunc(SomeClass input)
{
    Object output = null;

    if (inputIsValid(input))
    {
      //now actually do stuff!
      message = result_of_stuff_actually_done;
    } 

    return output;
}


private bool inputIsValid(SomeClass input)
{

    // *****************************************
    // convert these to guard style if you like   
    // ***************************************** 
    if(input != null)
    {
        SomeClass2 obj2 = input.getSomeClass2();
        if(obj2 != null)
        {
            SomeClass3 obj3 = obj2.getSomeClass3();
            if(obj3 != null && !BAD_OBJECT.equals(obj3.getSomeProperty()))
            {
                SomeClass4 = obj3.getSomeClass4();
                if(obj4 != null)
                {
                    int myVal = obj4.getSomeValue();
                    if(BAD_VALUE != myVal)
                    {
                        String message = this.getMessage(myVal);
                        if(MIN_VALUE <= message.length() &&
                           message.length() <= MAX_VALUE)
                        {
                            return true;
                        }
                    }
                }
            }
        }
    }
    return false;
}