只要条件为假,当我们要重复一组语句时,将使用Do..Until循环。
语法
VBScript中的Do..Until循环的语法:
Do Until condition [statement 1] [statement 2] ... [statement n] [Exit Do] [statement 1] [statement 2] ... [statement n] Loop
流程图
例
下面的示例使用Do..Until循环在循环开始时检查条件。仅当条件为false时,才执行循环内的Statements。当条件变为true时,它将退出循环。
<!DOCTYPE html> <html> <body> <script language = "vbscript" type = "text/vbscript"> i = 10 Do Until i>15 'Condition is False.Hence loop will be executed i = i + 1 Document.write("The value of i is : " & i) Document.write("<br></br>") Loop </script> </body> </html>
执行上述代码后,它将在控制台中输出以下输出。
The value of i is : 11 The value of i is : 12 The value of i is : 13 The value of i is : 14 The value of i is : 15 The value of i is : 16
备用语法
Do..Until循环还有一个备用语法,它在循环结束时检查条件。下文将通过示例说明这两种语法之间的主要区别。
Do [statement 1] [statement 2] ... [statement n] [Exit Do] [statement 1] [statement 2] ... [statement n] Loop Until condition
流程图
例
下面的示例使用Do..Until循环在循环结束时检查条件。即使条件为True,循环内的语句也至少执行一次。
<!DOCTYPE html> <html> <body> <script language = "vbscript" type = "text/vbscript"> i = 10 Do i = i + 1 Document.write("The value of i is : " & i) Document.write("<br></br>") Loop Until i<15 'Condition is True.Hence loop is executed once. </script> </body> </html>
执行上述代码后,它将在控制台中输出以下输出。
The value of i is : 11
作者:terry,如若转载,请注明出处:https://www.web176.com/vbscript/1268.html