嵌套循环

A nested loop is a loop within a loop, an inner loop within the body of an outer one. How this works is that the first pass of the outer loop triggers the inner loop, which executes to completion. Then the second pass of the outer loop triggers the inner loop again. This repeats until the outer loop finishes. a break within either the inner or outer loop would interrupt this process.

For Next 嵌套循环的结构是：

For counter1=startNumber to endNumber (Step increment)

    For counter2=startNumber to endNumber (Step increment)

        One or more VB statements

    Next counter2

Next  counter1

示例：

    For  firstCounter = 1 to 5

      Print `First Loop of ` + firstCounter

    For   secondCounter= 1 to 4

      Print `Second Loop of ` + secondCounter

    Next secondCounter

  Next firstCounter