IF expression THEN
      ...
   ELSE
      ...
   ENDIF
   IF expression THEN
      ...
   ELSEIF expression2 THEN
      ...
      ...
   ELSE
      ...
   ENDIF

Implement a conditional jump. This implementation assumes that an expression passed as a parameter is 0 (for false) and not zero (for true). In this case, if the expression is zero, it jumps directly to the statement following the corresponding ENDIF (or ELSE, if present). Otherwise, the following code will be executed (up to ENDIF or ELSE).

  IF ( x == 42 ) THEN : x = 0 : ELSE : x = 1 : ENDIF
  IF ( x == 42 ) THEN : x = 0 : ELSE IF y == 0 THEN : y = 42 : ELSE : x = 1 : ENDIF
  IF ( x == 42 ) THEN
    x = 0
  ELSE IF y == 0 THEN
    y = 42
  ELSE
    x = 1
  ENDIF

See also the following example files:

• control_returning_01.bas
• control_returning_02.bas
• control_popping_91.bas

 If...Th...El...Eif...Ei

• Atari (400/800)
• Atari XL/XE
• Commodore 128 (MOS 8502)
• Commodore 128 (Zilog Z80)
• Commodore 64
• Commodore 64+REU
• TRS-80 Color Computer
• TRS-80 Color Computer 3
• ColecoVision
• Amstrad CPC 664
• Dragon 32
• Dragon 64
• Thomson MO5
• Thomson MO5
• Olivetti Prodest PC128
• Commodore PLUS/4
• SEGA SC-3000
• SEGA SG-1000
• VG-5000
• Commodore VIC-20
• ZX Spectrum 48

If you have encountered a problem using this command, if you think there is a bug or the explanation is unclear, please open an issue for this keyword on GitHub. Thank you!