C # Check whether the string is a number

C # Check whether the string is a number

This log is composed
SamoolPosted on AM

Regular Expression
String RegEx = @ ^ \ D + $;

Write a method by yourself: This is what I wrote.
Private bool isnumber (string S)
{
Int flag = 0;
Char [] STR = S. tochararray ();
For (INT I = 0; I <Str. length; I ++)
{
If (char. isnumber (STR [I])
{
Flag ++;
}
Else
{
Flag =-1;
Break;
}
}
If (flag> 0)
{
Return true;
}
Else
{
Return false;
}
}

Test
Private void button#click (Object sender, system. eventargs E)
{
If (isnumber (textbox1.text. Trim ()))
{
Textbox2.text = is a number;
}
Else
{
Textbox2.text = not a number;
}
}

 

Try
{
Double. parse (this. textbox1.text );
Response. Write (number );
}
Catch
{
Response. Write (not a number );
}

You can also use a regular expression:
Using system. Text. regularexpressions;
------------------------
RegEx r = new RegEx (@ ^ \ D + (\.)? \ D * $ );
If (R. ismatch (this. textbox1.text ))
{
This. response. Write (a number );
}
Else
{
This. response. Write (not a number );
}

Public static bool strisint (string Str)
{
Try
{
Int32.parse (STR );
Return true;
}
Catch
{
Bool flag = false;
Return flag;
}
}

 

Regular expressions should be used:
String Pattern = @ ^ \ D + (\. \ D )? $;
If (text1.text. Trim ()! =)
{
If (! RegEx. ismatch (sign_money.text.trim (), pattern ))
{
Text1 is not a number;
}
Else
{
Text1 is a number;
}
}

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