关于String和StringBuilder比较
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
TextBox1.Text = ""
TextBox2.Text = ""
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim startTime As Long = DateTime.Now.Ticks
Dim myString As String = "This is"
Dim i As Integer
For i = 0 To 20
myString += myString
Next
Dim endTime As Long = DateTime.Now.Ticks
TextBox1.Text = (endTime - startTime) * 10
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim startTime As Long = DateTime.Now.Ticks
Dim myStringBuilder As New System.Text.StringBuilder(7)
myStringBuilder.Append("This is")
Static Dim i As Integer = 0
For i = 0 To 20
myStringBuilder.Append("This is")
i += 1
Next
Dim endTime As Long = DateTime.Now.Ticks
TextBox2.Text = (endTime = startTime) * 10
End Sub
End Class
这个比较有问题,何处有问题?谢谢