Editing C syntax (section)

====Type qualifiers====
{{main|Type qualifier}}
Types can be qualified to indicate special properties of their data. The type qualifier <code>[[const (computer programming)|const]]</code> indicates that a value does not change once it has been initialized. Attempting to modify a <code>const</code> qualified value yields undefined behavior, so some C compilers store them in [[rodata]] or (for embedded systems) in [[read-only memory]] (ROM). The type qualifier <code>[[volatile (computer programming)|volatile]]</code> indicates to an [[optimizing compiler]] that it may not remove apparently redundant reads or writes, as the value may change even if it was not modified by any expression or statement, or multiple writes may be necessary, such as for [[memory-mapped I/O]].