当控制退出循环时，vbscript 中的动态数组被清除 [英] Dynamic array in vbscript gets cleared when control comes out of loop

问题描述

我是 VBScript 的新手.我正在尝试使用 VBScript 中的动态数组概念，下面是我的代码.代码:

I am newbie to VBScript. I am trying my hands at Dynamic array concept in VBScript below is my code. Code:

dim arr()
For i = 0 To 3
    Redim arr(i+1,2)
    arr(i,0)=i
    arr(i,1)=i+1
    MsgBox arr(i,0)&"-"&arr(i,1)
Next
For i = 0 To UBound(arr)
    MsgBox arr(i,0)&" "&arr(i,1)
Next

一旦控制进入第二个循环，所有存储在 arr 中的值都将丢失.我不明白为什么以及如何?我试过添加 Preserve 关键字，但它抛出下标超出范围错误.TIA！！！

As soon as the control comes into second loop all the values stored in arr are lost. i do not understand why and how? I've tried adding Preserve keyword but it throws subscript out of range error. TIA!!!

推荐答案

[哎呀，漏掉了两个维度]使用 ReDim Preserve 而不是普通的 ReDim.(并去掉 Dim 语句中的 ().)[/哎呀]

[oops, missed the two dimensions] Use ReDim Preserve instead of plain ReDim. (And get rid of the () in the Dim statement.) [/oops]

您只能增长动态数组(不是用 (n[,m,..]) 变暗的固定数组).多维数组只能增长最后一维(文档).所以:

You can only grow dynamic arrays (not fixed arrays Dimmed with (n[,m,..])). A more dimensional array can only grow the last dimension (docs). So:

选项显式

ReDim arr(1, -1) ' <-- dynamic
Dim i
For i = 0 To 3
    ReDim Preserve arr(1, i) ' last dim grows
    arr(0, i) = i
    arr(1, i) = i + 1
Next
For i = 0 To 3
    WScript.Echo i & ":", arr(0, i), arr(1, i)
Next

输出:

cscript 29520636.vbs
0 0 1
1 1 2
2 2 3
3 3 4

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