PB入门教程A(11)

PB入门教程A

循环结构使得能够重复执行一行或多行代码，PowerBASIC支持以下几种循环结构

1. 原型：

FOR Counter = start TO stop [STEP increment] . {statements}

NEXT [Counter [, [Counter]] ...]

示例：

FOR n# = 1.0 TO 1.5 STEP 0.1 x$ = STR$(n#) NEXT n# 2. 原型：

WHILE integer_expression {statements} [EXIT LOOP] {statements} WEND 示例：

i& = 0

WHILE ISFALSE EOF(1) INCR i&

LINE INPUT #1, FileTxt$(i&) WEND

3. 原型：

DO [{WHILE | UNTIL} expression] {statements} …

[EXIT LOOP] [ITERATE LOOP] ...

LOOP {{WHILE | UNTIL} expression}

示例：

Count1 = 0

DO WHILE Count1 < 10 FOR Count2 = 0 TO 1 x = arry(Count1,Count2) Count1 = Count1 + 1 NEXT Count2 LOOP

DO…LOOP WHILE…WEND FOR…NEXT