Scala Loops
Sometimes, we may need to execute the same block of code multiple times. In general, statements are executed sequentially: the first statement in a function executes first, followed by the second statement, and so on.
Programming languages provide various control structures that allow for more complex execution paths.
Loop statements allow us to execute a statement or a group of statements multiple times. Below is a flowchart of loop statements in most programming languages:
Loop Types
The Scala language provides the following loop types. Click the links to view details of each type.
| Loop Type | Description |
|---|---|
| while loop | Runs a series of statements. If the condition is true, it repeats until the condition becomes false. |
| do...while loop | Similar to the while statement, except that it executes the loop's code block once before checking the loop condition. |
| for loop | Used to repeatedly execute a series of statements until a specific condition is met, generally implemented by incrementing a counter value after each loop iteration. |
Loop Control Statements
Loop control statements change the execution order of your code, and through them you can implement code jumps. Scala has the following loop control statements:
Scala does not support break or continue statements, but since version 2.8 it provides a way to break out of loops. Click the link below for details.
| Control Statement | Description |
|---|---|
| break statement | Breaks the loop |
Infinite Loops
If the condition is always true, the loop becomes an infinite loop. We can use the while statement to implement an infinite loop:
Example
def main(args: Array[String]) {
var a = 10;
// Infinite loop
while( true ){
println( "The value of a is : " + a );
}
}
}
After the above code is executed, the loop will run forever. You can use Ctrl + C to interrupt the infinite loop.
Other Extensions