Computer

QB64 - Programming statements

Loop/Iteration

process of repetition in programming

For...Next

• to perform a loop specific no. of times

• uses a counter variable jo is increased or decreased

• Syntax:

  For counter variable = Start Value To End Value Step

  Print whatever

  Next counter variable

• For = beginning of loop

• StartValue = actual value of variable

• EndValue= value the variable shd reach to end the loop

• StepValue = amount by which the variable changes after each loop

• Next = ends the loop

DO WHILE… LOOP

• performed as long as the given statement is true

• Before the loop is ended, counter variable shd be increased/decreased

• When step value is missing, it becomes an infinite loop!

• Syntax Example

  assign value to variable. a = 1

  Do while test condition Do while a<=10

  Statement 1 print a

  Statement 2 a = a+1

  Loop Loop

DO UNTIL…LOOP

• executed until a certain condition is met

• If,

  statement false = executed

  statement true = stops executing

• Syntax

  DO UNTIL test condtion

  Statement 1

  Statement 2

  LOOP

WHILE…WEND

• executes a series of statements until the condition is true

• Syntax

  WHILE test condition

  Statements

  WEND

EXIT

• Used to come out of a loop before the expected no. of times

• Generally followed by IF