title: What is {} + {} in JavaScript?
body: <p><strong>1st Part:</strong></p>
  
  <p>Because When you are adding two arrays, everything works as expected: </p>
  
  <pre><code> [] + []     //output:''
  </code></pre>
  
  <p>Adding an array and an object also conforms to our expectations: </p>
  
  <pre><code> [] + {}
  output:'[object Object]'
  </code></pre>
  
  <p><code>{} + {}</code> in JavaScript is <code>NaN</code> ?<br>
  and this is unexpected result so what is the reason behind this?</p>
  
  <p><strong>2nd part:</strong></p>
  
  <p>In string comparison without prefix 0, 3 is greater than 12: </p>
  
  <pre><code>"3" &gt; "12"
  : true
  </code></pre>
  
  <p>With padding, everything works correctly:</p>
  
  <pre><code> "03" &gt; "12"
  : false
  </code></pre>
  
  <p>Is prefix 0 compulsory for string comparision?What is the reason for adding prefix 0 ?</p>