title: Why does the printf prints nothing but an empty blank
body: <p>I've been trying to figure the problem but after 3 hours I quit, anyone have any suggestion how this problem might occur. Any help would be appreciated!
  Currently using codeblock 20.23. <a href="https://i.stack.imgur.com/rCSAb.png" rel="nofollow noreferrer">img of the empty blank</a></p>
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;stdbool.h&gt;
  int main()
  {
      int dd, mm, yy, temp = 0;
      bool isLeapYear = temp;
      printf(&quot;Enter the year: &quot;);
      scanf(&quot;%d&quot;, &amp;yy);
          if(yy &lt; 0)
          {
          printf(&quot;Year number cannot be smaller than 0!&quot;);
          return 0;
          } else
          {
              if(yy%4==0 &amp;&amp; yy%400==0 || yy%4==0)
              temp = 1;
          }
      printf(&quot;Enter the month: &quot;);
      scanf(&quot;%d&quot;, &amp;mm);
          if(mm &gt; 12 || mm &lt; 0)
          {
          printf(&quot;Month number cannot be smaller than 0 or bigger than 12!&quot;);
          return 0;
          }
      printf(&quot;Enter the date: &quot;);
      scanf(&quot;%d&quot;, &amp;dd);
          if(dd &gt; 30 || dd &lt; 0)
          {
          printf(&quot;Date number cannot be smaller than 0 or bigger than 30!&quot;);
          return 0;
          } else
          {
              if(dd == 29 &amp;&amp; mm == 2 &amp;&amp; temp == 0)
              printf(&quot;Since given year is not a leap year therefore your input date is invalid.&quot;);
              return 0;
          }
      printf(&quot;dd/mm/yy of your given number: %02d/%02d/%04d&quot;, dd, mm, yy);
      return 0;
  
  }
  </code></pre>