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-rw-r--r--c.html.markdown57
1 files changed, 30 insertions, 27 deletions
diff --git a/c.html.markdown b/c.html.markdown
index 23d97560..f5f28608 100644
--- a/c.html.markdown
+++ b/c.html.markdown
@@ -323,33 +323,6 @@ str_reverse(c);
printf("%s\n", c); // => ".tset a si sihT"
*/
-/*
-Functions are located in known memory addresses, so they can be called
-through function pointers. Syntax may be initially confusing.
-
-Example: use str_reverse from a pointer
-*/
-void str_reverse_through_pointer(char * str_in) {
- // Define a function pointer variable, named f.
- void (*f)(char *); // Signature should exactly match the target function.
- f = &str_reverse; // Assign the address for the actual function (determined at runtime)
- (*f)(str_in); // Just calling the function through the pointer
- // f(str_in); // That's an alternate but equally valid syntax for calling it.
-}
-
-/*
-As long as function signatures match, you can assign any function to the same pointer.
-Useful for passing handlers (or callback functions) around.
-Function pointers are usually typedef'd for simplicity and readability, as follows:
-*/
-
-typedef void (*my_fnp_type)(char *);
-
-// The used when declaring the actual pointer variable:
-// ...
-// my_fnp_type f;
-
-
///////////////////////////////////////
// User-defined types and structs
///////////////////////////////////////
@@ -390,6 +363,36 @@ int area(rect r){
return r.width * r.height;
}
+///////////////////////////////////////
+// Function pointers
+///////////////////////////////////////
+/*
+At runtime, functions are located at known memory addresses. Function pointers are
+much likely any other pointer (they just store a memory address), but can be used
+to invoke functions directly, and to pass handlers (or callback functions) around.
+However, definition syntax may be initially confusing.
+
+Example: use str_reverse from a pointer
+*/
+void str_reverse_through_pointer(char * str_in) {
+ // Define a function pointer variable, named f.
+ void (*f)(char *); // Signature should exactly match the target function.
+ f = &str_reverse; // Assign the address for the actual function (determined at runtime)
+ (*f)(str_in); // Just calling the function through the pointer
+ // f(str_in); // That's an alternative but equally valid syntax for calling it.
+}
+
+/*
+As long as function signatures match, you can assign any function to the same pointer.
+Function pointers are usually typedef'd for simplicity and readability, as follows:
+*/
+
+typedef void (*my_fnp_type)(char *);
+
+// The used when declaring the actual pointer variable:
+// ...
+// my_fnp_type f;
+
```
## Further Reading