{{htmlmetatags>metatag-robots=()
metatag-title=(FLOW CONTROL EXITING FROM NESTED LOOP | ugBASIC User Manual)
metatag-keywords=(ugBASIC,Commodore 64,Commodore PLUS/4,ZX Spectrum)
metatag-description=(An isomorphic language for retrocomputers)
metatag-media-og:image=(:ugbasic:logo-ugbasic-fb.png)
metatag-og:title=(FLOW CONTROL EXITING FROM NESTED LOOP | ugBASIC User Manual) 
metatag-og:description=(An isomorphic language for retrocomputers)
}}

====== ugBASIC User Manual ======

===== FLOW CONTROL EXITING FROM NESTED LOOP =====

==== PURPOSE ====
 This small example will use the ''DO...LOOP'' keywords to implement an endless loop, and the command ''EXIT n'' to break ''n'' loops. The outer loop will change, at each half of second, the border's color from black to yellow. The inner loop will change the color of border to red and green. Instead of continuing with the inner loop, this one (and the outer) will be exited by using the ''EXIT 2'' command.  The border color is changed using the ''COLOR BORDER'' instruction, using the predefined constants ''YELLOW'', ''BLACK'', ''RED'', ''GREEN''. To wait for a specific amount of time the ''WAIT'' command will be used, with the ''MS'' (milliseconds) unit of time.  

==== SOURCE CODE ====
   
      CLS
   
      DO
         COLOR BORDER YELLOW
         HOME: PRINT "YELLOW"
         WAIT 500 MS
         COLOR BORDER BLACK
         HOME: PRINT "BLACK "
         WAIT 500 MS
         DO
            COLOR BORDER RED
            HOME: PRINT "RED   "
            WAIT 1000 MS
            COLOR BORDER GREEN
            HOME: PRINT "GREEN "
            WAIT 1000 MS
            DO
               COLOR BORDER RED
               HOME: PRINT "RED   "
               WAIT 1000 MS
               EXIT 2 : REM EXIT 2 = skip 1 more loop, because "EXIT" == "EXIT 1"!
               REM The border will never be green,
               REM and the secondo loop will be skiped
               COLOR BORDER GREEN
               HOME: PRINT "GREEN "
               WAIT 1000 MS
            LOOP
         LOOP
      LOOP
   
   


==== SOURCE FILE ====
  * ''[[https://github.com/spotlessmind1975/ugbasic/tree/main/examples/control_loops_03.bas|control_loops_03.bas]]''
==== HOW TO COMPILE AND RUN ====
The instructions here refer to compiling the example from the command line. For Microsoft Windows users we suggest using **[[https://spotlessmind1975.itch.io/ugbasic-ide|UGBASIC-IDE]]**, which allows you to compile the example with just one click.=== ATARI 400/800 family ===
In order to compile and run the example, you need to have the Altirra emulator, and in particular that the ''altirra'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.atari control_loops_03.bas -o example.xex
   altirra example.xex
   
   # Windows 
   ugbc.atari.exe control_loops_03.bas -o example.xex
   altirra example.xex
=== ATARI 600XL/800XL/1200XL/XG(SE) family ===
In order to compile and run the example, you need to have the Altirra emulator, and in particular that the ''altirra'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.atarixl control_loops_03.bas -o example.xex
   altirra example.xex
   
   # Windows 
   ugbc.atarixl.exe control_loops_03.bas -o example.xex
   altirra example.xex
=== Commodore 64 ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''x64sc'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.c64 control_loops_03.bas -o example.prg
   x64sc example.prg
   
   # Windows 
   ugbc.c64.exe control_loops_03.bas -o example.prg
   x64sc example.prg
=== Commodore 64+REU ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''x64sc'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.c64reu control_loops_03.bas -o example.prg
   x64sc -reu example.prg
   
   # Windows 
   ugbc.c64reu.exe control_loops_03.bas -o example.prg
   x64sc -reu example.prg
=== Commodore PLUS/4 ===
== Using YAPE ==
In order to run the example, you need to have the YAPE emulator. In particular that the ''yape'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.plus4 control_loops_03.bas -o example.prg
   yape example.prg
   
   # Windows 
   ugbc.plus4.exe control_loops_03.bas -o example.prg
   yape example.prg
== Using VICE ==
In order to run the example, you need to have the VICE emulator. In particular that the ''xplus4'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.plus4 control_loops_03.bas -o example.prg
   xplus4 example.prg
   
   # Windows 
   ugbc.plus4.exe control_loops_03.bas -o example.prg
   xplus4 example.prg
=== Dragon 32 ===
In order to compile and run the example, you need to have the XROAR emulator, and in particular that the ''xroar'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.d32 control_loops_03.bas -o example.bin
   xroar -rompath (your rom path) example.bin
   
   # Windows 
   ugbc.d32.exe control_loops_03.bas -o example.bin
   xroar.exe -rompath (your rom path) example.bin
=== Dragon 64 ===
In order to compile and run the example, you need to have the XROAR emulator, and in particular that the ''xroar'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.d64 control_loops_03.bas -o example.bin
   xroar -rompath (your rom path) example.bin
   
   # Windows 
   ugbc.d64.exe control_loops_03.bas -o example.bin
   xroar.exe -rompath (your rom path) example.bin
=== PC128 Olivetti Prodest ===
In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the ''dcmoto'' executable is accessible.

Then, type this command on the command line and on the emulator:

   # Linux 
   ugbc.pc128op control_loops_03.bas -o example.k7
   dcmoto
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
   
   # Windows 
   ugbc.pc128op.exe control_loops_03.bas -o example.k7
   dcmoto
   (choose example.k7)
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
=== Thomson MO5 ===
In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the ''dcmoto'' executable is accessible.

Then, type this command on the command line and on the emulator:

   # Linux 
   ugbc.pc128op control_loops_03.bas -o example.k7
   dcmoto
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
   
   # Windows 
   ugbc.pc128op.exe control_loops_03.bas -o example.k7
   dcmoto
   (choose example.k7)
   (choose BASIC 128)
   CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
=== Commodore VIC-20 ===
In order to compile and run the example, you need to have the VICE emulator, and in particular that the ''xvic'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.vic20 control_loops_03.bas -o example.prg
   xvic --memory 24k example.prg
   
   # Windows 
   ugbc.vic20.exe control_loops_03.bas -o example.prg
   xvic --memory 24k example.prg
=== ZX Spectrum ===
In order to compile and run the example, you need to have the Speccy emulator, and in particular that the ''speccy'' executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.zx control_loops_03.bas -o example.tap
   Speccy example.tap
   
   # Windows 
   ugbc.zx.exe control_loops_03.bas -o example.tap
   Speccy example.tap
=== MSX ===
In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

== openMSX ==
   # Linux 
   ugbc.msx1 control_loops_03.bas -o example.rom
   openmsx -cart example.rom
   
   # Windows 
   ugbc.msx1.exe control_loops_03.bas -o example.rom
   openmsx -cart example.rom
== blueMSX ==
   # Linux 
   ugbc.msx1 control_loops_03.bas -o example.rom
   bluemsx example.rom
   
   # Windows 
   ugbc.msx1.exe control_loops_03.bas -o example.rom
   bluemsx example.rom
=== ColecoVision ===
In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

== openMSX ==
   # Linux 
   ugbc.coleco control_loops_03.bas -o example.rom
   openmsx -machine \"COL - ColecoVision\" -cart example.rom
   
   # Windows 
   ugbc.coleco.exe control_loops_03.bas -o example.rom
   bluemsx -machine \"COL - ColecoVision\" example.rom
== blueMSX ==
   # Linux 
   ugbc.coleco control_loops_03.bas -o example.rom
   bluemsx /machine \"COL - ColecoVision\" /rom1 example.rom
   
   # Windows 
   ugbc.coleco.exe control_loops_03.bas -o example.rom
   bluemsx  /machine \"COL - ColecoVision\" /rom1 example.rom
=== SEGA SC-3000 ===
In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.sc3000 control_loops_03.bas -o example.rom
   bluemsx /machine \"SEGA - SC-3000\" /rom1 example.rom
   
   # Windows 
   ugbc.sc3000.exe control_loops_03.bas -o example.rom
   bluemsx  /machine \"SEGA - SC-3000\" /rom1 example.rom
=== SEGA SG-1000 ===
In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

   # Linux 
   ugbc.sg1000 control_loops_03.bas -o example.rom
   bluemsx /machine \"SEGA - SG-1000\" /rom1 example.rom
   
   # Windows 
   ugbc.sg1000.exe control_loops_03.bas -o example.rom
   bluemsx  /machine \"SEGA - SG-1000\" /rom1 example.rom
==== ANY PROBLEM? ====
If you have found a problem trying to run this example, if you think there is a bug or, more simply, you would like it to be improved, [[https://github.com/spotlessmind1975/ugbasic/issues/new?title=IMPROVE FLOW CONTROL EXITING FROM NESTED LOOP|open an issue]] for this example on GitHub. Thank you!===== POWERED BY =====

[[:ugbasic:user:examples|{{ :ugbasic:user:logo-ugbasic.png?nolink&600 |}}]]