Difference between revisions of "GoTo"

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A command for [[:Category:Oblivion Script Extender|Oblivion Script Extender]]
A command for [[:Category:Oblivion Script Extender|Oblivion Script Extender]]
[[Category:OBSE Flow Control Functions]]
 
'''Syntax:'''
'''Syntax:'''
  GoTo ''[labelID]''
  GoTo ''[labelID]''


This command causes script processing to jump to a label defined within the same script. It is identical to [[RestoreIP]]. Use [[Label]] or [[SaveIP]] to define the instruction point to which to jump. Optional label IDs allow for multiple labels or nested loops within a script.
An alias for [[RestoreIP]]. This command causes script processing to jump to a label defined within the same script. Use [[Label]] or [[SaveIP]] to define the instruction point to which to jump.  
 
 
 
'''Basic Example:'''
<pre>
short count
 
set Count to GetActiveEffectCount
 
Label
 
if ( count > 0 )
 
  if GetNthActiveEffectCaster count == player
    messagebox "Player put a Hex on me!"
  endif
 
set count to count - 1
 
Goto
endif
 
</pre>
 
 
Optional label IDs allow for multiple labels or nested loops within a script.


Example:
'''Example:'''
<pre>begin onActivate
<pre>begin onActivate
     ; declare a variable to keep track of the number of times we've gone through the loop
     ; declare a variable to keep track of the number of times we've gone through the loop
Line 68: Line 94:


==Notes==
==Notes==
* These functions are considered "beta", and may be unreliable. Further testing is needed.
* Issues may arise when two or more scripts use the same label codes.
* Be careful to make sure your loop has an exit condition, otherwise you run the risk of creating an infinite loop, which can freeze the game and make it impossible for the player to exit.
* Be careful to make sure your loop has an exit condition, otherwise you run the risk of creating an infinite loop, which can freeze the game and make it impossible for the player to exit.
* For the most part, scripts will run one at a time and different scripts can use the same label IDs without any problems. However, result scripts and scripts with onActivate blocks will run instantly when called via script ([[SetStage]] and '''''ObjectRef.Activate player, 1''''', respectively), before the next line of code proceeds. For those two script types, make sure the IDs are unique.
** If you use a label ID in the calling script, and then the same ID in the called script, the ID will be set to the location in the called script. If the calling script uses '''''Goto ID''''', when that ID is set to another script, it will act as a [[Return]].


==See Also==
==See Also==
[[Label]]
*[[Label]]
[[SaveIP]]
*[[SaveIP]]
[[RestoreIP]]
*[[RestoreIP]]


<!--[[Category: OBSE Functions]]
[[Category:OBSE Flow Control Functions]]-->


[[Category: OBSE Functions]]
[[Category:Functions]]
[[Category:Functions (OBSE)]]
[[Category:Miscellaneous Functions]]
[[Category:Miscellaneous Functions (OBSE)]]

Latest revision as of 03:04, 11 September 2009

A command for Oblivion Script Extender

Syntax:

GoTo [labelID]

An alias for RestoreIP. This command causes script processing to jump to a label defined within the same script. Use Label or SaveIP to define the instruction point to which to jump.


Basic Example:

short count

set Count to GetActiveEffectCount

Label

if ( count > 0 )

  if GetNthActiveEffectCaster count == player
    messagebox "Player put a Hex on me!"
  endif

set count to count - 1

Goto
endif


Optional label IDs allow for multiple labels or nested loops within a script.

Example:

begin onActivate
    ; declare a variable to keep track of the number of times we've gone through the loop
    long var
    set var to 0
   
    ; save the current instruction pointer
    ; this records that the beginning of the loop is right before the PrintToConsole command
    SaveIP ; could also use Label
   
    ; print the current loop count
    PrintToConsole "loop %f" var
   
    ; update the loop counter
    set var to var + 1
   
    ; we only want to go through the loop three times, so check the loop counter
    if var < 3
        ; jump back to the saved location
        RestoreIP ; could also use Goto
    endif
   
    ; if we get here, we're done with the loop
end

When activated, this script will print:

loop 0.0000
loop 1.0000
loop 2.0000

To support nested loops, the SaveIP and RestoreIP commands take an optional integer parameter specifying which 'slot' to save the instruction location in. If you don't specify a number, it defaults to 0. There are 256 slots in the internal list.

A more familiar For-loop in a normal programming language would look like this:

for (i = 0; i < 5; i++)
{
  for (j = 0; j < 3 ; j++)
  {
    //Do Something
  }
}

To create the same loop using OBSE functions:

short i
short j

Label 0 ; top of outer loop, equivalent to SaveIP 0
  set j to 0
  Label 1 ; top of inner loop
    PrintToConsole "i = %.0f, j = %.0f" i, j
    set j to ( j + 1 )
    if ( j < 3 )
      GoTo 1 ; equivalent to RestoreIP 1
    endif
  set i to ( i + 1 )
  if ( i < 5 )
    GoTo 0
  endif

Note that unless the above loop is wrapped inside a conditional statement or a block like OnActivate, it will restart the very next frame and every frame thereafter.

Notes[edit | edit source]

  • Be careful to make sure your loop has an exit condition, otherwise you run the risk of creating an infinite loop, which can freeze the game and make it impossible for the player to exit.
  • For the most part, scripts will run one at a time and different scripts can use the same label IDs without any problems. However, result scripts and scripts with onActivate blocks will run instantly when called via script (SetStage and ObjectRef.Activate player, 1, respectively), before the next line of code proceeds. For those two script types, make sure the IDs are unique.
    • If you use a label ID in the calling script, and then the same ID in the called script, the ID will be set to the location in the called script. If the calling script uses Goto ID, when that ID is set to another script, it will act as a Return.

See Also[edit | edit source]