if
FORMULA
The if statement decides what code to execute next.
Parameters
This statement has one parameter:
formula – is a formula that decides whether or not to execute the following statements. The result of this formula must be a Boolean (true/false) value.
Description
The if statement is the basic building block for making decisions in a Panorama program . The if statement will skip over the next few statements (up to the next else, elseif or endif statement) if the true/false formula is false. Here’s a simple example.
if City=""
City="Pismo Beach"
State="CA"
endif
message City+", "+State
Depending on what’s in the City field, this procedure can work one of two ways. If the City field is empty, the true/false formula
City=""
will be true, so the procedure will perform the assignments
City="Pismo Beach"
State="CA"
But if the City field is not empty, the true/false formula will be false, and Panorama will skip past the endif to the message statement.
In this example there are two statements between the if and endif statements. These two statements will be skipped if the formula is false. However, there is no limit to the number of statements that may be between the if and endif statements. Just make sure that there is always a matching endif for every if. Although it is not required, indenting the statements between the if and the endif usually makes the procedure easier to read and understand.
Nested IF Statements
Pairs of if-endif statements can be nested inside each other, like this:
if State=""
State="CA"
if City=""
City="Pismo Beach"
endif
endif
message City+", "+State
There is no limit to how many levels deep you can nest if-endif pairs, but be sure that each if statement is matched by a corresponding endif statement.
Error Messages
IF or ELSE without ENDIF – Each IF statement must be paired with a corresponding ENDIF statement. If this error message appears, the necessary endif statement has not been included.
See Also
- call -- allows a procedure to call a separate procedure within the current database as a subroutine.
- call( -- allows a procedure to be called as a subroutine within a formula and return a result.
- calledby( -- returns true if this function is in code called by the specified database, the specified procedure, or both.
- callerslocalvariablevalue( -- allows a subroutine to access a local variable in the procedure that called it.
- callingdatabase( -- returns the name of the database that called this procedure as a subroutine, if any.
- callingprocedure( -- returns the name of the procedure that called this procedure as a subroutine, if any.
- callwithin -- allows a procedure to call a mini-procedure within a separate procedure within the current database as a subroutine.
- callwithin( -- allows a "mini-procedure" to be called as a subroutine within a formula and return a result.
- callwithindatabase( -- returns true if the current procedure was called by another procedure in the same database, false if it was called by a procedure in another database.
- case -- allows multiple decisions to be chained together (also see the elseif statement).
- catch -- works with try and endcatch to trap errors in a sequence of statements.
- Custom Database Initialization -- using an .Initialize procedure to automatically run custom code when a database opens.
- debug -- stops the current program, allowing you to examine variables or single step.
- defaultcase -- works together with the case statement to specify statements that will be executed if none of the *case* statements are true.
- disableabort -- prevents loops from being stopped early by pressing SHIFT-COMMAND-ESCAPE or by exceeding the maximum allowed loop time.
- else -- works together with the if statement to specify statements that will be executed for both the *true* and *false* cases.
- elseif -- allows multiple if decisions to be chained together.
- enableabort -- allows the SHIFT-COMMAND-ESCAPE key sequence to stop an endless loop.
- endcase -- marks the end of statements controlled by a previoius case statement.
- endcatch -- works with try and catch to trap errors in a sequence of statements.
- endif -- marks the end of statements controlled by a previoius if statement.
- endloop -- is used at the end of a loop.
- Error Handling -- Techniques for trapping runtime errors instead of letting them abort the program.
- Error Wizard -- Advanced dialog for displaying program errors.
- execute -- allows a procedure to call a sequence of statements within the current procedure as a "mini-subroutine".
- execute( -- allows a formula to execute a sequence of statements and return a result.
- executeasap -- executes the specified code at the first possible opportunity, non-atomically.
- executecatcherrors -- is the same as the execute statement, except for the fact that if an error occurs while running, it can be trapped by an if error statement immediately following the executecatcherrors statement.
- executelocal -- is the same as the execute statement, but it shares local variables with the procedure that called it.
- farcall -- allows a procedure to call a separate procedure within a different database as a subroutine.
- farcallwithin -- allows a procedure to call a mini-procedure within a separate procedure in a different database as a subroutine.
- for -- is used at the beginning of a loop that loops a fixed number of times.
- goto -- allows a procedure to arbitrarily jump from one spot to another
within the procedure.
- info("callerslocalvariables") -- returns a list of local variables defined in the procedure that called the current procedure.
- info("error") -- returns the most recent error message.
- info("labels") -- lists the labels in the current procedure.
- info("procedurestack") -- returns the contents of Panorama's procedure call stack.
- loop -- is used at the beginning of a loop.
- looparray -- is used at the beginning of a loop that loops over the elements of an array.
- loopdataarray -- is used at the beginning of a loop that loops over the elements of a data array.
- loopindex -- allows a procedure to determine how many times a loop has been repeated.
- loopwhile -- is used at the beginning of a loop.
- noimplicitassignment -- does nothing, and is only retained for compatibility with earlier versions.
- nop -- does nothing (**n**o **op**eration).
- onerror -- can be used to catch all errors that are not trapped by if error or try statements.
- onfailedresume -- is used to setup a semi-graceful recovery if a resume statement fails because there was no pause statement.
- parameter( -- is used to transfer data between a main procedure and a subroutine.
- pause -- temporarily pauses a procedure.
- Preventing Endless Loops -- setting up a timeout limit to prevent endless loops.
- quit -- quits Panorama.
- repeatloopif -- decides whether to continue with a loop or to start over again from the top.
- resume -- resumes a procedure that has been temporarily halted with the pause statement.
- resumeaftertask -- resumes after a waitfortask statement.
- return -- ends a subroutine.
- returnerror -- passes an error back to the current subroutines calling procedure.
- setcallerslocal -- allows a subroutine to modify a local variable in the procedure that called it.
- seterror -- changes the error message returned by info("error").
- setparameter -- is used to transfer data from a subroutine back to the main
procedure that called it.
- setwaitinglocal -- assigns a value to a local variable in the parent procedure of an asynchronous task, allowing the asynchronouse code to pass a value back to the code that spawned it.
- shortcall -- allows a procedure to call a sequence of statements within the current procedure as a "mini-subroutine".
- stop -- stops all running procedures immediately.
- stoploopif -- decides whether to continue with a loop or to exit the loop immediately.
- throwerror -- causes an immediate error.
- try -- works with catch and endcatch to trap errors in a sequence of statements.
- until -- is used at the end of a loop, and can control how many times the loop is executed.
- usecallerslocalvariables -- temporarily swaps out a subroutine's current local variables with the local variables of the procedure that called this subroutine. The statement can be used only in a subroutine, not in a calling procedure.
- usefunctioncallerslocalvariables -- temporarily swaps out a procedures current local variables with the local variables of the procedure that called this the call(, callwithin( or execute( function.
- usemylocalvariables -- reverses the action of the UseCallersLocalVariables statement, switching back to the current procedure's normal local variables.
- waitfortask -- temporarily pauses a procedure until the specified task is complete.
- while -- is used at the end of a loop, and can control how many times the loop is executed.
History
| 10.0 | No Change | Carried over from Panorama 6.0. |