C# - Zero Based String error

Question

It comes up with this error when I try to login.

Index (zero based) must be greater than or equal to zero and less than the size of the argument list.

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        //string name = textBox1.Text;
        string.Format ("{0} {1}", "Best", "Regards");

        if (textBox1.Text == "Ryan" && textBox2.Text == "password")
        {
            MessageBox.Show(string.Format("Welcome {1}" ));
        }

    }
}

Sorry you were right. I flagged it myself. – Mr.B Apr 30 '13 at 14:12 — Mr.B, Apr 30 '13 at 14:12

score 8 · Accepted Answer · answered Apr 30 '13 at 12:43

8

string.Format("Welcome {1}" )

needs an argument

string.Format("Welcome {0}", textBox1.Text )

answered Apr 30 '13 at 12:43

Sayse

42,633
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this stopped the error. but what is the point in have it if it doesnt showing up the text I told it {0} which is "best". Or have I misunderstood what this completely does? – Mr.B Apr 30 '13 at 13:14
? please help as Im pretty confused now – Mr.B Apr 30 '13 at 13:18
I think you have misunderstood what the 0 does, the zero is a reference to an argument that is found after the comma, here is a pretty good example http://www.techotopia.com/index.php/Formatting_Strings_in_C_Sharp – Sayse Apr 30 '13 at 13:46
it is only "best" for your first `string format` – Sayse Apr 30 '13 at 13:53

score 5 · Answer 2 · answered Apr 30 '13 at 12:43

The error is thrown in this line:

MessageBox.Show(string.Format("Welcome {1}" ));

because you have used the placeholder {1} but havn't provided an argument to the string.Format function. Beside that you have not started with the index 0.

You have to provide an argument and start with the index 0:

MessageBox.Show(string.Format("Welcome {0}", textBox1.Text));

score 3 · Answer 3 · answered Apr 30 '13 at 12:44

3

You need to do the following:

string.Format("Welcome {0}", "some value here");

answered Apr 30 '13 at 12:44

Ric

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score 2 · Answer 4 · answered Apr 30 '13 at 12:43

2

MessageBox.Show(string.Format("Welcome {0}", "some text"));

answered Apr 30 '13 at 12:43

burning_LEGION

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C# - Zero Based String error

4 Answers4