Data commit

Task/Pointers-and-references/C/pointers-and-references-1.c

@@ -0,0 +1,2 @@
+int var = 3;
+int *pointer = &var;

Task/Pointers-and-references/C/pointers-and-references-10.c

@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct {
+    int val;
+} num;
+
+int addNodes(num **array, int elems);
+
+int main(void) {
+    int numElems, i;
+    num *arr = NULL;
+    numElems = addNodes(&arr, 10);
+    for (i = 0; i < numElems; i++) {
+        printf("%d) %d\n", i+1, arr[i].val);
+    }
+    free(arr);
+    return 0;
+}
+
+int addNodes(num **array, int elems) {
+    num *temp = NULL;
+    int i;
+    for (i = 0; i < elems; i++) {
+        temp = realloc(*array, (i+1) * sizeof **array);
+        if (temp == NULL) {
+            free(*array); return -1;
+        } else {
+            *array = temp;
+        }
+        (*array)[i].val = i;
+        // Alternatives:
+        // ((*array)+i)->val = i; // or
+        // (*((*array)+i)).val = i;
+    }
+    return i;
+}

Task/Pointers-and-references/C/pointers-and-references-2.c

@@ -0,0 +1,2 @@
+int v = *pointer; /* sets v to the value of var (i.e. 3) */
+*pointer = 42; /* sets var to 42 */

Task/Pointers-and-references/C/pointers-and-references-3.c

@@ -0,0 +1,2 @@
+int othervar;
+pointer = &othervar;

Task/Pointers-and-references/C/pointers-and-references-4.c

@@ -0,0 +1 @@
+pointer = NULL; /* needs having stddef.h included */

Task/Pointers-and-references/C/pointers-and-references-5.c

@@ -0,0 +1 @@
+pointer = 0; /* actually any constant integer expression evaluating to 0 could be used, e.g. (1-1) will work as well */

Task/Pointers-and-references/C/pointers-and-references-6.c

@@ -0,0 +1 @@
+pointer = (void*)0; /* C only, not allowed in C++ */

Task/Pointers-and-references/C/pointers-and-references-7.c

@@ -0,0 +1,4 @@
+int array[10];
+pointer = array;
+/* or alternatively: */
+pointer = &array[0];

Task/Pointers-and-references/C/pointers-and-references-8.c

@@ -0,0 +1,2 @@
+pointer += 3; /* pointer now points to array[3] */
+pointer -= 2; /* pointer now points to array[1] */

Task/Pointers-and-references/C/pointers-and-references-9.c

@@ -0,0 +1,5 @@
+v = pointer[3]; /* accesses third-next object, i.e. array[4] */
+v = pointer[-1]; /* accesses previous object, i.e. array[0] */
+/* or alternatively */
+v = *(pointer + 3); /* array[4] */
+v = *(pointer - 1); /* array[0] */