title: What is an Integer constant expression in C programming?
body: <p>While reading answers for a question, I came across this answer <a href="https://stackoverflow.com/a/49712550/15933960">https://stackoverflow.com/a/49712550/15933960</a>  . This answer contains this following statement -</p>
  <blockquote>
  <p>An <strong>integer constant expression</strong> with the value 0, or such an expression cast to type void *, is called a null pointer constant. If a null pointer constant is converted to a pointer type, the resulting pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function.</p>
  </blockquote>
  <p>In this statement, What does the term <strong>Integer constant expression</strong> mean?</p>