Trapdoor In The Sun

Alan Shanahan, Technician & Consultant

Tag Archives: if statement


by 2 Comments

Force.com: Apex Styleguide, Part 3

Click here for Part 1 of this series.
Click here for Part 2 of this series.

Here, I’m going to take a look at the condition part of the if statement. In particular, how best to write a complex condition to allow for readability and easy code maintenance. Sometimes even just a small number of ANDs and ORs can be easy to write but difficult to untangle later. Add in some brackets for changes in operator priority and the picture becomes even worse. I will refrain from filling up this post with words because I think the example below will provide most of the colour and information I’m trying to impart on the topic.

if (conditionA || (conditionB && conditionC) || (conditionD || conditionE)) {
  doSomething();
}

Figure 1, above, equates to the following:

if A OR (B AND C) OR (D OR E) then do something

When you substitute the conditions for real-world variables, function/method calls or complex structure sub-fields, the results can be less than legible. But, apply a little indentation and split your conditions up and you suddenly have some clarity.

if (
       conditionA
       ||
       (
           conditionB
           &&
           conditionC
       )
       ||
       (
           conditionD
           ||
           conditionE
       )
   ) {
  doSomething();
}

Figure 2, above, is functionally identical to Figure 1. Do you think it’s more readable? Easier to maintain?

A little tip for those engaged in writing complex Force.com custom formula fields with if statements: try using the same method .

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Force.com: Apex Styleguide, Part 2

If you haven’t already seen Part 1 of this series, click here to go to it.

Example 2, if/then/else Statements in Apex:

This article deals with the humble if/then/else statement, specifically the executable part of the statement. As before, I’m writing in Apex code, so there may be minimal syntactical differences between this and similar, related languages e.g. C & variants, Java, etc.

We can start with a simple, common binary use of the if statement:

if (a == b) runSomething();
else runSomethingElse();

Figure 1, above, is a simple case of “if a = b then run something, otherwise run something else“. It looks perfectly fine.

if (a == b)
  runSomething();
else
  runSomethingElse();

Figure 2, above, is almost identical to Figure 1 except that the executable part of the if and else clauses are on separate lines and indented. A little better. More readable, perhaps, and functionally identical.

if (a == b) {runSomething(); } else { runSomeThingElse(); }

Figure 3, above, has expanded on Figure 1. The addition of block braces around the executable sections serve to demarcate the runnable parts of the code.

if (a == b) {runSomething(); andSomethingElse(); } else { runSomeThingElse(); andRunAFourthThing(); }

Figure 4, above, is an example of where the programmer has added some extra method calls into the two executable blocks. This would not be possible for Figure 1 and Figure 2 above without the addition of braces.

if (a == b) {
  runSomething();
}
else {
  runSomethingElse();
}

Figure 5, above, is where we FINALLY come to the version that I’m happy with. The if and else clauses are on their own lines, block braces surround the executable sections of both clauses and indentation completes the picture.

if (a == b) {
  runSomething();
  andRunSomethingElse();
}
else {
  runSomethingElse();
  andRunAFourthThing();
}

Figure 6, above, is a clear illustration of how easy it is to add two method calls without upsetting any of the surrounding lines of code in Figure 5. No braces need to be added because they are already there. The value of this style is that you may wish to add multiple lines within any of the code blocks; this makes it very easy to do and retains code legibility.

As ever, please feel free to post your comments, whether you agree with me or not.