JSTL c out does not print a scriptlet variable

Question

In the following code snippet c:out is not working.

<%!
String myVariable="This is working";
%>
myVariable=='<c:out value="${myVariable}"/>'
myVariable=='<%= myVariable%>'

Output

myVariable==''

myVariable=='This is working'

The output in c:out tag coming as empty.Could you explain the reason for this?