ugBASIC User Manual

   FOR var = start TO end [ STEP increment ]
      ...
   NEXT [var]

The FOR…NEXT is a basic tool for executing a block of code a specified number of times. It is a control structure that creates a loop, which is a segment of code that is repeated until a certain condition is met. Once inside the loop, the index used to loop can be read and modified by the program as if it is a normal variable.

Normally, the index counter is increased by 1 unit at every turn of a FOR…NEXT loop. When the current value exceeds that of the last number specified, the loop is terminated. STEP is used to change the size of increase in the index value.

The FOR…NEXT loop is ideal for performing the same operation a specific number of times. It can be used to create tables of values, such as a multiplication table. It is often used in algorithms that require repeated calculations, such as calculating the factorial of a number. Generally speaking, you can use the FOR…NEXT when you know the number of iterations in advance, want to perform a sequence of operations repetitively and you need a simple and effective control structure.

  i = 0
  FOR i = 1 TO 100 STEP 2
     PRINT i
  NEXT

See also the following example files:

• control_controlled_01.bas
• control_controlled_02.bas

 FoNx

• 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

DO...LOOP WHILE...WEND REPEAT...UNTIL

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!