Sub Main()
Dim testStrings() As String = New String() {Nothing, "", String.Empty}
For Each str As String In testStrings
TestStringSpeed(str, 10000000)
Console.WriteLine("=======================")
Next
End Sub
Private Sub TestStringSpeed(ByVal str As String, ByVal count As Integer)
Dim n As Integer = count
Dim sw As New Stopwatch
Console.WriteLine("str Is Nothing")
sw.Start()
For i As Integer = 1 To n
If str Is Nothing Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Console.WriteLine("str = Nothing")
sw.Reset() '更多.net源码和教程,来自[乐博网 www.]
sw.Start()
For i As Integer = 1 To n
If str = Nothing Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Console.WriteLine("str = """"")
sw.Reset()
sw.Start()
For i As Integer = 1 To n
If str = "" Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Console.WriteLine("str = String.Empty")
sw.Reset()
sw.Start()
For i As Integer = 1 To n
If str = String.Empty Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Console.WriteLine("str Is String.Empty")
sw.Reset()
sw.Start()
For i As Integer = 1 To n
If str Is String.Empty Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Console.WriteLine("String.IsNullOrEmpty(str)")
sw.Reset()
sw.Start()
For i As Integer = 1 To n
If String.IsNullOrEmpty(str) Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Try
Console.WriteLine("str.Length = 0")
sw.Reset()
sw.Start()
For i As Integer = 1 To n
If str.Length = 0 Then
End If
Next
Console.WriteLine("花費時間: " & sw.ElapsedMilliseconds)
Catch ex As Exception
End Try
End Sub