GraphCalc scripts support two types of control structures, if/else and while. These commands work just like they do in other programming languages. Keep in mind that commads, as with most of GraphCalc's features are case sensitive.

The if/else structure allows for a true/false condition to determine which set of commands to follow. Note that the ElseIf and Else sections are optional. Here is the syntax:

If(boolean condition)
  Commands
ElseIf(boolean condition)
  Commands
Else
  Commands
EndIf

The while structure allows for looping of a set of commands while a boolean condition is true. Here is the syntax:

While(boolean condition)
  Commands
EndWhile

One additional command that is often useful in controlling the execution of scripts is the ExitScript command which ceases execution of the script.

Here is an example of a trivial script showing conditional statements:

    If(irand(0:100) > 50)
      [Comment="If"]
    ElseIf(irand(0:10) < 5)
      [Comment="first ElseIf"]
    ElseIf(irand(0:10) > 5)
      [Comment="second ElseIf"]
    Else
      [Comment="Else"]
    EndIf
    

And an example of a trivial script showing a while loop:

    i=irand(1:10)
    While(i > 0)
     i=i-irand(1:4)
     i=i+irand(1:2)
    EndWhile