Do...Loop
Positron8 · Revision 4.0.6.5 · PDF pages 302–303
Syntax
Do Instructions Loop
or
Do Instructions Loop Until Condition
or
Do Instructions Loop While Condition
Overview
Execute a block of instructions until a condition is true, or while a condition is false, or create an infinite loop.
Example 1
Device = 18F26K40 ' Tell the compiler what device to compile for
Declare Xtal = 16 ' Tell the compiler the device will be operating at 16MHz
Declare Hserial_Baud = 9600 ' Choose the Baud rate for HRsoutLn
Dim MyWord as Word
MyWord = 1
Do ' Create a loop
HRsoutLn Dec MyWord
DelayMs 200
Inc MyWord
Loop Until MyWord > 10 ' Loop until MyWord is greater than 10Example 2
Device = 18F26K40 ' Tell the compiler what device to compile for
Declare Xtal = 16 ' Tell the compiler the device will be operating at 16MHz
Declare Hserial_Baud = 9600 ' Choose the Baud rate for HRsoutLn
Dim MyWord as Word
MyWord = 1
Do ' Create a loop
HRsoutLn Dec MyWord
DelayMs 200
Inc MyWord
Loop While MyWord < 11 ' Loop while MyWord is less than 11
Example 3
Device = 18F26K40 ' Tell the compiler what device to compile for
Declare Xtal = 16 ' Tell the compiler the device will be operating at 16MHz
Declare Hserial_Baud = 9600 ' Choose the Baud rate for HRsoutLn
Dim MyWord as Word
MyWord = 1
Do ' Create a loop
HRsoutLn Dec MyWord
DelayMs 200
Inc MyWord
Loop ' Loop foreverNotes.
Do-Loop differs from the While-Wend type in that, the Do loop will carry out the instructions within the loop at least once like a Repeat-Until type, then continuously until the condition is true, but the While loop only carries out the instructions if the condition is true.
Do-Loop is an ideal replacement to a For-Next loop, and can actually take less code space, thus performing the loop faster.
The above example 2 and example 3 show the equivalent to the For-Next loop: -
For MyWord = 1 to 10 : NextSee also : While...Wend, For...Next...Step, Repeat...Until.
