title: How to ask say "or" in an if-statement
body: <pre><code>private void caseTextBox_TextChanged(object sender, EventArgs e)
          {
              var CTcase = caseTextBox.Text;
              caseTextBox.CharacterCasing = CharacterCasing.Upper;
  
              if (CTcase == "THRUHOLE") 
              {
                  displayLabel3.Text = "0";
              }
              else if (CTcase == "EIAA")
              {
                  displayLabel3.Text = "1";
              }
              else if (CTcase == "EIAB")
              {
                  displayLabel3.Text = "2";
              }
              else if (CTcase == "EIAC")
              {
                  displayLabel3.Text = "3";
              }
              else if (CTcase == "EIAD")
              {
                  displayLabel3.Text = "4";
              }
              else
              {
                  displayLabel3.Text = "error";
              }
          }
  </code></pre>
  
  <p>In each statement there are 3 values that it could equal to display the correct number. But I don't want to write 15 <code>if</code>/<code>else</code> statements to make it work. I tried using <code>||</code>, <code>|</code>, <code>&amp;</code>, and <code>&amp;&amp;</code>. But I keep getting an error that says</p>
  
  <blockquote>
    <p>Operator cannot be applied to operands of type 'bool' and 'string'</p>
  </blockquote>
  
  <pre><code> private void caseTextBox_TextChanged(object sender, EventArgs e)
          {
              var CTcase = caseTextBox.Text;
              caseTextBox.CharacterCasing = CharacterCasing.Upper;
  
              if (CTcase == "THRUHOLE") 
              {
                  displayLabel3.Text = "0";
              }
              else if (CTcase == "EIAA" || "1206")
              {
                  displayLabel3.Text = "1";
              }
  </code></pre>