Index and length must refer to a location within the string.

Question

0.00/5 (No votes)

See more:

Hi! I need to learn substrings etc and I'm a novice in ASP.net and I have this code

C#

protected void Page_Load(object sender, EventArgs e)
  {
      if (!Page.IsPostBack)
      {
          TextBox1.Text = "RHR 100";
      }


  }
  protected void Button1_Click(object sender, EventArgs e)
  {
      string myString = TextBox1.Text.ToString();
      string substring = myString.Substring(0, 3);
      string substring2 = myString.Substring(3, 6);

      Label1.Text = "Substring[0,3]: " + substring;
      Label2.Text = "Substring[3,6]: " + substring2;


  }

and when I click on the button. Label 1 should be RHR and Label 2 should be 100 but it keeps having this error

SQL

Index and length must refer to a location within the string.
Parameter name: length

Why is this so? Thank you! :)

Posted 15-Mar-13 4:45am

BeastMode10

Updated 6-May-21 6:05am

Add a Solution

Comments

[no name] 15-Mar-13 10:49am

You are asking the SubString for a string starting at 3 with a length of 6 and your string is not that long. You want SubString(3, 3)

3 solutions

Solution 3

// what if we can't know the length of the string...

string substring2 = SafeSubstring(myString, 3, 6);

public string SafeSubstring(string sSafeString, int iStart, int iLength)
{
// Replacement for Visual Basic function Mid().
// Unlike .Substring function, Mid() doesn't make error when start character
// position or end character is outside of string. If so, it returns 'string.Empty'.
// IMPORTANT: SafeSubstring() starts from character 0, Mid() from 1.

string sSubstring = string.Empty;

int iStringLen = sSafeString.Length;
int iPointer = iStart;

if (iStringLen > 0 & iStart >= 0 & iStart < iStringLen & iLength > 0)
{
while (iPointer < iStart + iLength & iPointer < iStringLen)
{
sSubstring += sSafeString.Substring(iPointer, 1);
iPointer += 1;
}
}
return sSubstring;
}

Posted 6-May-21 6:05am

Kuromuro

Updated 6-May-21 6:11am

v2

Comments

CHill60 6-May-21 12:09pm

Rather than resurrecting such an old post with this it might have been better to post it as a Tip. You would of course have to add some commentary and format your code.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Mike Meinz · Accepted Answer · 2013-03-15T04:51:00

Solution 1

The second parameter of String.Substring is length. I changed the 6 to a 3.

C#

string myString = TextBox1.Text.ToString();
string substring = myString.Substring(0, 3);
string substring2 = myString.Substring(3, 3);

See String.Substring Method (Int32, Int32)[^]

Posted 15-Mar-13 4:51am

Mike Meinz

Updated 15-Mar-13 4:52am

v2

Comments

BeastMode10 15-Mar-13 11:16am

Thank you! :)

Sandeep Mewara · Accepted Answer · 2013-03-15T04:53:00

Solution 2

This is incorrect:

C#

string substring2 = myString.Substring(3, 6);

First parameter: Starting position
Second parameter: No of characters to extract (i.e. it has to be such that it does not goes out of string's length overall.) Hope you get the logic.

Thus, it should be:

C#

string substring2 = myString.Substring(3, 3);

Refer: MSDN: String.Substring Method (Int32, Int32)[^]

Posted 15-Mar-13 4:53am

Sandeep Mewara

Comments

BeastMode10 15-Mar-13 11:15am

Thank you so much!

Sandeep Mewara 15-Mar-13 11:49am

Welcome.