Initial commit

ForNextDay/Lec5/src/debug.c

@@ -0,0 +1,25 @@
+// pointing.c
+/*
+ * Never dereference an unitialized pointer!
+ *
+ * Assigning a value to an unitialized pointer much worse!
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#define DEBUG 0
+
+int main(int argc, char * * argv)
+{
+  int a = 5;
+  int b = 17;
+  int* pa;
+  int* pb;
+  // what happens if you leave these two statements out? Why?
+  pa = &a;
+  pb = &b;
+
+  #if DEBUG > 0
+  printf("main: a = %d, b = %d, argc = %d\n", *pa, *pb, argc);
+  #endif
+  return EXIT_SUCCESS;
+}

ForNextDay/Lec5/src/forscope.c

@@ -0,0 +1,18 @@
+// forscope.c
+/*
+ * - Should this compile? Why/why not?
+ * - What will the output be?
+ * - Explain the output.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char** argv)
+{
+  int i = 0;
+  for(int i=0;i<5;i++){
+    printf("%d\n",i);
+  }
+  printf("%d\n",i);
+  return EXIT_SUCCESS;
+}

ForNextDay/Lec5/src/ifscope.c

@@ -0,0 +1,28 @@
+// ifscope.c
+/*
+ * Should this compile? Why/why not?
+ * What will the output be if:
+ *    (i) i=1, j=2
+ *    (i) i=2, j=1
+ */
+#include <stdio.h>
+#include <stdlib.h>
+int main(int argc, char** argv)
+{
+  int iErr;
+  int i;
+  int j;
+
+  printf("Enter two integers: ");
+  iErr = scanf("%d %d", &i, &j);
+  if(iErr != 2)
+  {
+    fprintf(stderr,"Egads - something went wrong!\n");
+    return EXIT_FAILURE;
+  }
+  if(i>j){
+    int i = 0;
+    printf("%d\n",i);
+  }
+  return EXIT_SUCCESS;
+}

ForNextDay/Lec5/src/pointing.c

@@ -0,0 +1,20 @@
+// pointing.c
+/*
+ * Never dereference an unitialized pointer!
+ *
+ * Assigning a value to an unitialized pointer much worse!
+ */
+#include <stdio.h>
+#include <stdlib.h>
+int main(int argc, char * * argv)
+{
+  int a = 5;
+  int b = 17;
+  int* pa;
+  int* pb;
+  // what happens if you leave these two statements out? Why?
+  pa = &a;
+  pb = &b;
+  printf("main: a = %d, b = %d, argc = %d\n", *pa, *pb, argc);
+  return EXIT_SUCCESS;
+}

ForNextDay/Lec5/src/swap.c

@@ -0,0 +1,21 @@
+// swap.c
+/*
+ */
+#include <stdio.h>
+#include <stdlib.h>
+void swap(int i, int j);
+
+int main(int argc, char* argv[]) {
+   int i = 10;
+   int j = 99;
+   printf("i = %d; j = %d\n", i, j);
+   swap(i,j);
+   printf("i = %d; j = %d\n", i, j);
+   return EXIT_SUCCESS;
+}
+void swap(int i, int j) {
+   int swap;
+   swap = i;
+   i = j;
+   j = swap;
+}