title: Strange format specifier in c with percentage character
body: <p>I have a question related to a "printf" instruction in a c example:</p>
  
  <pre><code>printf("Percentage character: %%",10);
  </code></pre>
  
  <p>The output is correct: Percentage character: %</p>
  
  <p>Why is that format-specifier (%%)?  What is with that 10 over there? Why the compiler says that are too many arguments for <code>printf</code>?</p>
  
  <p>I tried to display the percentage character in another way:</p>
  
  <pre><code>printf("Percentage character: %c",putch(37));
  </code></pre>
  
  <p>However,the output is not really good: %Percentage charcater: %</p>
  
  <p>Why it appears that percentage character before the sentence?</p>