Swift & Network programmability, a good combo? An introduction.

I know quite some programming languages and I do like programming languages that are powerfull but also so easy to use that it allows me to quickly convert my flow-thoughts (what should the program do at which moment) in a quick and easy way. That’s probably one of the reasons why I have a preference for Java (nice object-oriented), Omnis (a fourth generation english like programming language or FileMakerPro (database solution with powerfull scripting options). 

It is clear that Swift has taken the things from other programming languages that work and leave those that do not work. That makes it difficult to transition sometimes (between versions) but the language is evolving in the good direciton. Let me share some things that describe the expressivity of Swift.

Safety & if statement
As I mentioned, if there is a variable, Swift’s safety ensures that the variable must have a value. Unless you make the variable optional with the question mark. But what if that variable doesn’t have a value and you use it. You get an error. So a common programming principle is to first check if the variable is set, in Java this would be.

// Check if the variable is set
if myvariable != null {
  // check if the variable has value 10
   if myVariable == 10 {
      System.out.print("Variable is 10")
   }
}

Within Swift, these two if-statements can be combined into a single statement:

In this Swift statement, I use the “let” keyword to assign the value of myVariable to myNewVariable. And only if that is succesfull, the check is done on myNewValue. And I can print do what I need. This expression helps you to minimize the nesting of if-statements. 

Returning two values from one function
Another example that I do like is returning a tuple of values instead of a classic value. Traditionally you would need a special class, create that class and then return the value. In swift, I just specify that I want to return a tuple of values and return it. I can then check on both values with the return. This mechansim provides quite some flexibility in returning for example an error code (Integer) and the response of a REST-API call or some other value. The code would be

If I execute this function, I can check on the result value and then process the response. And I can use that result and response label in my code, so the code remains readable.

Array’s
I also found that the Array object within Swift is actually very powerfull (that is because of generics, but that is truely an advanced topic). It is really easy to search through arrays within Swift. I will give just one example:

So this short for loop immediately has a check and matches on the where statement, so that the for loop is only entered for every command (within the ciscoConfigLines) that matches the where clause. For me that is really expressive.

Another example is to make an array of classes that each can have other attributes as well. It is really easy to loop through those arrays and execute tasks on the value.