1. Scala Tutorial
2. Scala Overview
3. Scala Classes
4. Scala Singleton and Companion Objects
5. Scala Applications
6. Scala Variables
7. Scala Data Types
8. Scala Arrays
9. Scala if
10. Scala while
11. Scala for
12. Scala Exceptions + try catch finally
13. Scala Match Expressions
14. Compiling Scala with Ant

• if - else
• Omitting { } in if - statements
• if - statements as Functions

The Scala if command executes a certain block of code, if a certain condition is true. Here is an example:

var myInt : Int = 0;

if(myInt == 0) {
  println("myInt == 0");
}

This example would print the text "myInt == 0" to the console.

The expression inside the paranthesis must result in a boolean value (true or false). For instance, if you call a method inside the parenthesis, that method must return a boolean value.

if - else

You can add an else to an if condition, like this:

var myInt : Int = 1;

if(myInt == 0) {
    println("myInt == 0");
} else {
    println("myInt != 0");
}

Omitting { } in if - statements

Like in Java it is possible to omit the {} in an if-statement around the code to execute, if the code consists of a single line. Here is an example:

var myInt : Int = 1;

if(myInt == 0)
    println("myInt == 0");
 else
    println("myInt != 0");

if - statements as Functions

In Scala if-statements can be used as functions. That is, they can return a value. Here is an example:

var myInt : Int = 1;

var myText : String =
   if(myInt == 0) "myInt == 0";
   else           "myInt != 0";

println(myText);

Notice how the myText variable is assigned to the result of the if-statement.

The if-statement returns the last value assigned inside it. Thus, in this case, since else-clause is executed, the last value assigned is the "myInt !=0". If the if or else clause had more than one statement in them, remember that only the last assignment would be returned.

Since if-statements behave like functions, you can use them in any place you could normally use a function.