Expression
Instruction vs Expression
Instruction tells the computer to do something, such as changing a variable, printing in the console, etc.
Expression is something that has a value or a type.
For exemple:
var aCondition = true;
val aConditionValue = if(aCondition) 5 else 3
It's a IF Expression
. It always returns a value.
IF Expression
is very useful in Scala.
Everything in Scala is an Expression.
Code block
The code block is an expression. The value of a code block is that of the its last expression.
val aCodeBlock = {
val z = 3
if (z > 2) "hello" else "bye"
}
The value or variable declared inside the code block can't be accessed by the outside.