Flow of control Index
Running instructions Conditionals
Terminators Multitasking
Passing control Logical operators

 

Running instructions Top
APPLY applies a parameter list to a procedure
FOR runs a list for a defined number of times
FOREACH runs a list for each element of a list replacing ? with the element name
IGNORE ignore the output of a procedure
REPEAT runs a runlist repeatedly
RUN runs a list
WAIT waits for a number of milliseconds
WHILE runs a list until a condition is false
Conditionals Top
ELSE part of the IF command
IF runs a list based on a condition
IF runs a list based on a condition
IFFALSE (IFF) runs a list if TEST was false
IFTRUE (IFT) runs a list if TEST was true
TEST test a condition. Used with IFTRUE and IFFALSE
THEN part of the IF command
Terminators Top
BYE, EXIT, QUIT ends Logo
OUTPUT halts a procedure and outputs a value
RESTART restarts Logo and sets all defaults
STOP terminates a procedure
TOPLEVEL returns to toplevel
Multitasking Top
HALT halts background procedures
LAUNCH launches a background procedure
Passing Top
:ERROR contains the code of the last runtime error
:ERRORTEXT contains the text of the last runtime error
CATCH catches runtime errors
GO jumps to a label inside a procedure
LABEL marks a target for the GO command
THROW throws a runtime error
Logical operators Top
AND performs a logical AND
NOT negates its input
OR performs a logical OR on its input