Keyword For

Declares the start of a For/Next loop.

Syntax

For Local IndexVar := start_value To end_value [ Step constant_value ]
Statements...
Next

For Local IndexVar := start_value Until end_value [ Step constant_value ]
Statements...
Next

For Local IndexVar := Eachin value_set
Statements...
Next

Description

For declares the start of a For/Next loop, allowing for iteration through a set of values or objects.

There are three variants of the For/Next loop, modifying the values of the index variable via the range keywords below:

To: Iterates through the given start and end values;
Until: This variant of For/Next stops iterating before the last value in the loop, useful for iterating through zero-based arrays. (See Example 3.)
Eachin: Iterates through a set of objects or values, such as a list or array;

In the To and Until variants, the optional Step keyword, followed by a constant value, allows control over the size of the iteration step.

Alternatives to the closing Next keyword are End For, or simply End.

Example

For k=1 To 1000
    Print k
Next

' With optional Step

For k=1 To 1000 Step 100
    Print k
Next

' Alternative syntax examples

For k=1 To 1000
    Print k
End

For k=1 To 1000
    Print k
End For

Example 2

' Assume m:MyObject and mylist:List

For m=Eachin mylist
Print m.myField
Next

' Assume i:Int and myarray:Int[]

For i=Eachin myarray
Print myarray[i]
Next

Example 3

NUM = 100 ' Assume myarray[NUM] has been declared

' Prints 0 to 99 without requiring NUM-1

For k=0 Until NUM
Print myarray[k]
Next