Question

我正在编写一个Ceasaer函数，它接受一个字符串并通过Ceasear密码的变体运行它，并返回编码的文本。出于某种原因，我在声明没有特定边界的数组上得到索引超出范围错误。为什么我会遇到此异常，我该如何解决？

VB.NET代码：

Public Shared Function Ceaser(ByVal str As String) As String
    Dim r As String = ""
    Dim ints() As Integer = {}
    Dim codeints As Integer() = {}
    Dim codedints As Integer() = {}
    Dim ciphertext As String = ""
    For i As Integer = 0 To str.Length - 1
        Dim currentch As Integer = Map(str(i))
        ints(i) = currentch 'Where exception is happening
    Next
    Dim primes As Integer() = PrimeNums(ints.Length)
    For i As Integer = 0 To primes.Length - 1
        codeints(i) = ints(i) + primes(i) - 3
    Next
    For i As Integer = 0 To codeints.Length - 1
        Dim currentnum As Integer = codeints(i) Mod 27
        codedints(i) = currentnum
    Next
    For i As Integer = 0 To codedints.Length - 1
        Dim letter As String = rMap(codeints(i))
        ciphertext += letter
    Next
    Return ciphertext
End Function

Answer 1

您必须先指定数组边界才能访问其元素：

Dim ints As Integer(str.length-1)

将使用n个元素实例化数组，其中n = string str的长度。

（注意：VB .NET数组长度从零开始，因此使用array(0)实例化包含1个元素的数组。

您必须相应地采用其他数组。

为什么我的索引超出范围异常？

1 个答案: