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the mark of sucessful software

18 Sep

Right, so I’ve been thinking about this for a while now. It’s a question that has been contemplated more times than anyone cares to remember, and still we have no good way of achieving the goal that it sets out. A quick search on Amazon will probably yield a thousand books on the subject – each and every one making you think the next is the holy grail. So am I going to tell you the question?? Well I suppose I must.

What is successful software? I’m sure the exact definition of this is subject to opinion and means different things to different people. Therefore all I can do is bore you with the details of what I think makes successful software:

  1. Software that the end user is happy with – a no brainer, if no one wants to buy or use it then you may as well give up. Happiness encompasses how the software looks, the user experience, and the functionality.
  2. Software that is finished to schedule – no one likes to wait, from management to clients, and even developers. Software that is late causes stress on everyone. Scheduling is hard and it has to be realistic. The end result of cramming and cutting corners is poor quality.
  3. Software of high quality – you can finish on time but if it doesn’t do what it needs to do in a manner the user expects, or simply is littered with bugs, then there is not much to be cheerful about. It has been documented ([1]) that bugs caught early can mean 1 hours spent now can save up to 3 to 10 hours later. As a result bugs caught after release cost between 40-50% more. This is always worth keeping in mind.
  4. Software that is cost effective – achieving all three things above but at a cost which prevents profit does not make sense. Costs are important and developers should also be mindful of this – even for internal software.
  5. The developers are happy and proud – I’m sure there are many employers that would be happy if they got software that satisfied the first four criteria but couldn’t give shit how their employees felt or what it took (out) of them. Stressed out employees are no good, they will only leave, and sooner rather than later you will find that you can no longer attract those employees that are smart and get things done. It’s surprising how easy it is to keep people happy without spending a lot of money.
  6. The management are happy and proud – if all the above is achieved at the expense of a stressed out, worn out, nerve shattered manager, then the same problems that arise with unhappy developers can be seen in management with the same negative results.

Now that we have a definition of successful software we can ask the natural question of how to achieve this. As I mentioned earlier, there are more books that I care to read telling me how to do this. Yet I feel none of them can apply in every situation. They all preach some methodology from the latest fad to the decidedly idiotic. If any one of these methodologies actually conclusively worked, there would not be as many books. I’m convinced that the truth lies somewhere in between them all and depends not only on the organisation, but on the people involved. So surely those involved in creating the software may have a better perspective on what will work than the author of a book? (This is not to say you can’t steal ideas that you have read and apply them in a suitable manner.)

I have my opinions on what I think would work for me, and is something that I can probably document in a follow up post. For the moment I will leave this with the statement that don’t be frightened to break rules and invent your own when something is not working. This is the only way we can make our software more successful.

[1] Rapid Development – Steve McConell

7 ways to write beautiful code

3 Dec

I’ve noticed that the developer and designer community appear to be obsessed with lists. Is this for a reason that I have somehow missed? For example, over at dZone, 2 out of the top 3 most popular articles are lists: 15 CSS Tricks That Must be Learned and 10 Dirty Little Web Development Tricks – incidentally I liked both articles so I seem to have this obsession myself. OK this is not that many but hey I’ve seen loads of lists elsewhere. Anyway, I thought I would embrace this culture to feed my own addiction and I have detailed 7 (I was only going to do 5, and 6 was out as it’s not prime ;-) ) ways to write beautiful code.

First things first here, I’m talking about pure aesthetics, nothing else. As I have said previously, good code starts by being something other people find easy to read. In fact, Jeff Attwood had a blog post comparing coding to writing citing several sources. I urge you to take a look.

Anyway on to my list.

  1. Return from if statements as quickly as possible.

    For example, consider the following JavaScript function, this just looks horrific:

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    function findShape(flags, point, attribute, list) {
        if(!findShapePoints(flags, point, attribute)) {
            if(!doFindShapePoints(flags, point, attribute)) {
                if(!findInShape(flags, point, attribute)) {
                    if(!findFromGuide(flags,point) {
                        if(list.count() > 0 && flags == 1) {
                              doSomething();
                        }
                    }
                }
           }
        }   
     }

    Instead we can change the above to the following:

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    function findShape(flags, point, attribute, list) {
        if(findShapePoints(flags, point, attribute)) {
            return;
        }
     
        if(doFindShapePoints(flags, point, attribute)) {
            return;
        }
     
        if(findInShape(flags, point, attribute)) { 
            return;
        }
     
        if(findFromGuide(flags,point) {
            return;
        }
     
        if (!(list.count() > 0 && flags == 1)) {
            return;
        }
     
        doSomething();
     
    }

    You probably wouldn’t even want a function like the second one, too much going on (see point 7), but it illustrates exiting as soon as you can from an if statement. The same can be said about avoiding unnecessary else statements.

  2. Don’t use an if statement when all you simply want to do is return the boolean from the condition of the if.

    Once again an example will better illustrate:

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    function isStringEmpty(str){
        if(str === "") { 
            return true;
        }
        else {
            return false;
        }
    }

    Just remove the if statement completely:

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    function isStringEmpty(str){
        return (str === "");
    }
  3. Please use whitespace it’s free!

    You wouldn’t believe the amount of people that just don’t use whitespace – you would think there was a tax associated with using it. Again another example and I hesitate to say this but this is from real live code (as was the first example), all I have done is change the programming language and some function names – to protect the guilty:

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    function getSomeAngle() {
        // Some code here then
        radAngle1 = Math.atan(slope(center, point1));
        radAngle2 = Math.atan(slope(center, point2));
        firstAngle = getStartAngle(radAngle1, point1, center);
        secondAngle = getStartAngle(radAngle2, point2, center);
        radAngle1 = degreesToRadians(firstAngle);
        radAngle2 = degreesToRadians(secondAngle);
        baseRadius = distance(point, center);
        radius = baseRadius + (lines * y);
        p1["x"] = roundValue(radius * Math.cos(radAngle1) + center["x"]);
        p1["y"] = roundValue(radius * Math.sin(radAngle1) + center["y"]);
        pt2["x"] = roundValue(radius * Math.cos(radAngle2) + center["y"]);
        pt2["y"] = roundValue(radius * Math.sin(radAngle2) + center["y");
        // Now some more code
    }

    I mean I won’t bother putting an example of how it should be – it should just be sooo bloody obvious. That said, I see code like this ALL the time and so certain people do not find it that easy to judge how to use whitespace. Screw it, for them I will inject some whitespace into the example and it’s shown below.

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    function getSomeAngle() {
        // Some code here then
        radAngle1 = Math.atan(slope(center, point1));
        radAngle2 = Math.atan(slope(center, point2));
     
        firstAngle = getStartAngle(radAngle1, point1, center);
        secondAngle = getStartAngle(radAngle2, point2, center);
     
        radAngle1 = degreesToRadians(firstAngle);
        radAngle2 = degreesToRadians(secondAngle);
     
        baseRadius = distance(point, center);
        radius = baseRadius + (lines * y);
     
        p1["x"] = roundValue(radius * Math.cos(radAngle1) + center["x"]);
        p1["y"] = roundValue(radius * Math.sin(radAngle1) + center["y"]);
     
        pt2["x"] = roundValue(radius * Math.cos(radAngle2) + center["y"]);
        pt2["y"] = roundValue(radius * Math.sin(radAngle2) + center["y");
        // Now some more code
    }
  4. Don’t have useless comments:

    This one can get quite irritating. Don’t point out the obvious in comments. In the example below everyone can see that we’re getting the students id, there is no need to point it out.

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    function existsStudent(id, list) {
        for(i = 0; i < list.length; i++) {
           student = list[i];
     
           // Get the student's id
           thisId = student.getId();
     
           if(thisId === id) {
               return true;
           }
        }
        return false;   
    }
  5. Don’t leave code that has been commented out in the source file, delete it.

    If you are using version control, which hopefully you are – if not why not! – then you can always get that code back easily by reverting to a previous version. There is nothing more off putting when looking through code and seeing a large commented out block of code. Something like below or even a large comment block within a function itself.

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    //function thisReallyHandyFunction() {
    //      someMagic();
    //      someMoreMagic();
    //      magicNumber = evenMoreMagic();
    //      return magicNumber;
    //}
  6. Don’t have overly long lines.

    There is nothing worse than when you look at code that has lines that go on forever – especially with sample code on the internet. The number of times I see this and go ahhhhhhhhhh (I’ll switch to Java for this, as generics makes this particularly easy to do):

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    public static EnumMap<Category, IntPair> getGroupCategoryDistribution(EnumMap<Category, Integer> sizes, int groups) {
            EnumMap<Category, IntPair> categoryGroupCounts = new EnumMap<Category,IntPair>(Category.class);
     
            for(Category cat : Category.values()) {
                categoryGroupCounts.put(cat, getCategoryDistribution(sizes.get(cat), groups));
            }

    I’m not suggesting the 70 characters width that you had to stick to on old Unix terminals but a sensible limit like say 120 characters makes things a little easier. Obviously if you are putting sample code on the internet and you have it within a fixed width container, make it easier for people to read by actually having it fit in the container.

  7. Don’t have too many lines within a function/method.

    Believe it or not a few years ago now an old work colleague exclaimed that Visual C++ was “shit” as it didn’t allow you to have a method with more than 10,000 lines. I kid you not – well ok I can’t remember the exact number of lines but it was huge. I still see this time and time again where a function/method is at least 50 lines long. Can anyone tell me this is easy to follow? Not only that but it normally forms part of an if statement that you can never find the enclosing block because you are scrolling. To me anything over 30-35 lines is pretty hard to follow and requires scrolling. My recommendation is if it’s more than 10-15 lines consider splitting it up.

This is by no means an exhaustive list and I could have gone on longer – in fact my abolish the switch statement motto would have been number 8 if I had not already mentioned it before. However, it has to end somewhere but feel free to state your own annoyances and maybe I can update the post with some more.

Over and out.