比较字符串

Question

我想两个字符串在vb.net Windows应用程序

Imports System.Windows 

Public Class Form1 

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
     Dim s As String = "$99" 
     Dim y As String = "$9899" 
     If s > y Then 
      MessageBox.Show("Hi") 


     End If 
    End Sub 
End Class 

谁能一个纠正的逻辑，如果有任何错误在比较？

Answer 1

你是什么意思按长度或内容比较？

dim result as string 
dim s as string = "aaa" 
dim y as string = "bbb" 
if s.length = y.length then result = "SAME" '= true 
if s = y then result = "SAME" '= false 
MessageBox.Show(result) 

Answer 2

您正在比较字符串，而不是整数。

您可以将它们作为整数进行比较，将“$”替换为“”，然后将其转换为整数。

替换$为 “”

s = s.Replace("$", ""); 
y = y.Replace("$", ""); 

转换他们都为整数

Dim result1 As Integer 
Dim result2 As Integer 

result1 = Convert.ToInt32(s) 
result2 = Convert.Toint32(y); 

然后，你可以做

if (result1 > result2) { ... }

Answer 3

Dim sum1 As Int32 = 99 
    Dim sum2 As Int32 = 9899 
    'this works as expected because you are comparing the two numeric values' 
    If sum1 > sum1 Then 
     MessageBox.Show("$" & sum1 & " is greater than $" & sum2) 
    Else 
     MessageBox.Show("$" & sum2 & " is greater than $" & sum1) 
    End If 

    'if you really want to compare two strings, the result would be different than comparing the numeric values' 
    'you can work around this by using the same number of digits and filling the numbers with leading zeros' 
    Dim s As String = ("$" & sum1.ToString("D4")) '$0099' 
    Dim y As String = ("$" & sum2.ToString("D4")) '$9899' 
    If s > y Then 
     MessageBox.Show(s & " is greater than " & y) 
    Else 
     MessageBox.Show(y & " is greater than " & s) 
    End If 

我推荐总是使用整数来表示数值，特别是如果你想比较它们。比较数字值后，可以将值格式化为字符串。