title: Why does expr "i==i" fail with "invalid bareword"?
body: <p>1) </p>
  
  <pre><code>% expr "1==1"
  1
  </code></pre>
  
  <p>2) </p>
  
  <pre><code>% expr "i==i"
  invalid bareword "i"
  in expression "i==i";
  should be "$i" or "{i}" or "i(...)" or ...
  </code></pre>
  
  <p>Why am getting this error in step - 2</p>
  
  <pre><code>1) % if {"i" == "i"} {
      puts "hai"
    }
    hai
  
  
  
  2) % if {i == "i"} {
     puts "hai"
    }
  
  invalid bareword "i"
  in expression "i == "i"";
  should be "$i" or "{i}" or "i(...)" or ...
  </code></pre>
  
  <blockquote>
    <blockquote>
      <blockquote>
        <p>if {"i" == "i"} This is wotking with if condition . </p>
      </blockquote>
    </blockquote>
  </blockquote>
  
  <p>Here I found like expr command evaluating only integers , not comparing strings , But the In "if" condition everything (integer as well as string) are evaluating .</p>
  
  <p>How Things are working here ?</p>