make more progress on c pointers transcript

blog/posts/basics-c-pointers/TRANSCRIPT.md

@@ -12,16 +12,48 @@ Things pointers make easy:
 
 * Allowing a function to "modify a variable"
 * Dynamic memory allocation
-* Representation of data structures
+* Representation of abstract structures
 
-How do I declare a pointer?
+How do I declare a pointer variable?
 ---------------------------
 
+    int x = 10;
+    int *p = &x;
+    printf("p is a memory address. See? %p\n", p);
+
+    -----
+
+    int x = 10;
+    int *p;
+    p = &x;
+    printf("p is a memory address. See? %p\n", p);
+
+    -----
+
+    int x = 10;
+    int *p = &x;
+
+    // %ld represents a long int for printf
+    printf("Size of a pointer to int: %ld\n", sizeof(p));
+    printf("Size of int: %ld\n", sizeof(*p));
 
 
 What does it mean to 'dereference' a pointer?
 ---------------------------------------------
 
+    "Retrieve the value p is pointing at"
+    "The value associated with the memory address p"
+
+    int x = 10;
+    int *p = &x;
+    *p = 20;
+    printf("The value is: %d\n", *p);
+
+    // THIS IS WRONG
+    int *p;
+    *p = 10;
+
+
 How do I handle pointers inside a function?
 -------------------------------------------
 

blog/posts/basics-c-pointers/ex1.c

@@ -0,0 +1,9 @@
+#include<stdlib.h>
+#include<stdio.h>
+
+int main(){
+  int *p;
+  //*p = 10;
+  printf("The value is: %ld\n", sizeof(*p));
+  return 0;
+}