c# for() loop setting the increment up to the last character in a string : <p>I am taking a c# course and this is what it whats me to do:</p>

<p>"Create a string variable named decodedString and set it equal to the contents of the StringTextBox.
Create a string variable named encodedString to hold the encoded string and set it equal to an empty string.  We will build up the encoded values letter-by-letter in this variable.
Use a for() loop to loop through all of the characters in decodedString.  Your loop index "i" should start at 0 and increment up to the last character in decodedString."</p>

<p>I'm confused on how I stop the loop at the last character in <em>decodedString</em>.
Heres my short bit of code. </p>

<pre><code>        private void EnocodeButton_Click(object sender, EventArgs e)
    {

        String decodeString = StringTextBox.Text;
        String encodeString = "";
        for(int i=0,i== )    //Im not sure what to do here?
    }
</code></pre>
