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28 This construct causes the sequence of zero or more statements to be repeatedly executed. However, execution of the loop may be terminated using an Exit Do statement at which point control will transfer to the first statement following the Loop statement. Note that the Do-Loop compound statement may be nested and the Exit Do only terminates the innermost Do-Loop that contains it. Example Do <other-statements> Do <other-statements> If (i > 5) Then <other-statements> Exit Do End If Loop <other-statements> Loop Here, the Exit Do only terminates the inner Do-Loop; the outer one continues to iterate. There are four other variations on this basic looping concept, all of which involve a condition for continuing the iteration. The syntax of the four variations is as follows: Do While <boolean-expression> [<statements>] Loop Do Until <boolean-expression> [<statements>] Loop Do [<statements>] Loop While <boolean-expression> Do [<statements>] Loop Until <boolean-expression> As you can see, the difference between the four variations is whether the test is at the top of the loop or at the bottom of the loop and, secondly, the logic sense of the condition. Testing the condition at the top of the loop means that the statements within the loop may be executed zero or more times. Testing the condition at the bottom of the loop means that the statements will always be executed at least once. The difference between using While and Until is nothing more than a logic inversion. The construct Do While Not <boolean-expression> is logically equivalent to Do Until <boolean-expression>. There is no fixed limit on how deeply Do loops may be nested. The actual limit is governed by how much memory is available to the compiler. For all practical purposes, there is no limit. BasicX Compatibility Note In BasicX mode, the nesting of Do loops is limited to 10 for compatibility.