Exercise 12

Makefile

@@ -1,6 +1,6 @@
 CFLAGS=-Wall -g
 CC=gcc
-NAME=ex11
+NAME=ex12
 RUNCMD=./out/$(NAME)
 
 all: clean compile

ex10.c

@@ -22,18 +22,24 @@ int main(int argc, char *argv[])
 	int num_states = 4;
 	puts("Printing our own array of strings:");
 	for(i = 0; i < num_states; i++) {
-		printf("state %d: %s\n",i, states[i]);
+        char * state = states[i];
+		if('W' == *state) {
+			printf("Detected Washington. Exiting early (ex12 Extra Credit #3)\n");
+			break;
+		} else {
+			printf("state %d: %s\n",i, state);
+		}
 	}
 
 	////////////////////////////////////////////////////////////////////
-	// EXTRA CREDIT
+	printf("** EXTRA CREDIT\n");
 
 	// 1) Figure out what kind of code you can put in the parts of a for-loop
 
 	// 2) Look up how to use the comma character to separate multiple
 	// statements in parts of the for-loop.
 	// http://stackoverflow.com/q/276512/7507
-	puts("multiple initializers");
+	puts("Testing for statement with multiple initializers");
 	int j = 0;
 	for(i = 0, j = 100; i < num_states; i++, j += 5) {
 		printf("state %d: (%d) %s\n", i, j, states[i]);

ex11.c

@@ -6,6 +6,13 @@ int main(int argc, char *argv[])
 
 	int i = 0;
 	while(i < argc)  {
+		char *arg = argv[i];
+		// Ex12 Extra Credit #3
+		if(*arg == 'Z') {
+			printf("Detected argument starting with 'Z'! ");
+			printf("Not printing any more command line arguments...\n");
+			break;
+		}
 		printf("arg %d: %s\n", i, argv[i]);
 		i++;
 	}

ex12.c

@@ -0,0 +1,61 @@
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+	int i = 0;
+
+	if(argc == 1) {
+		// As per Extra Credit item #4
+		printf("You didn't enter any command-line arguments. You suck.\n");
+
+	} else if(argc > 1 && argc < 4) {
+		printf("Here are your arguments:\n");
+
+		for(i = 1; i < argc; i++) {
+			printf("%s ", argv[i]);
+		}
+		printf("\n");
+	} else if(argc > 4 && argc < 10) {
+		// Extra credit #2.
+		printf("That's a lot of arguments. I'll print them anyway.\n");
+		while(i < argc) {
+			printf("%s ", argv[i]);
+			i++;
+		}
+		printf("\n");
+	} else {
+		puts("You have too many arguments. You suck.\n");
+	}
+
+	// Extra credit #2
+	if(argc > 1) {
+		if(*argv[1] == 'Z') {
+			printf("You entered the secret character. Congratuations!\n");
+		}
+	}
+
+	//////////////////////////////////////////////////////////////////////////
+	printf("** EXTRA CREDIT\n");
+
+	// 1) Research the "boolean operators"
+	// Technically, they are &&, || and !, but since since C uses 
+	// numeric values for conditional tests, technically any operator
+	// that returns a numeric value can be used in this manner.  
+	// I.e. &, | and ^.
+	if(1 & 0) { printf("1 & 0 = \"true\"\n"); } else { printf("1 & 0 = \"false\"\n"); }
+	if(1 | 0) { printf("1 | 0 = \"true\"\n"); } else { printf("1 | 0 = \"false\"\n"); }
+	if(1 ^ 1) { printf("1 ^ 1 = \"true\"\n"); } else { printf("1 ^ 1 = \"false\"\n"); }
+	// Let's test if these operators are "short circuit" like in Java...
+	if(1 > 0 && printf("If you see this, then C does not \"short circuit\" conditionals.\n")) {
+		printf("short circuit test: true\n");
+	} else {
+		printf("short circuit test: false\n");
+	}
+
+	// 2) Add some more test cases (see above).	
+ 	// 3) Go back to ex10 and ex11. Add if-statements to make loops exit early
+ 	// using break.
+ 	// 4) Fix the first test so the message accurately explains to the user
+ 	// that they didn't enter any arguments.	
+	return 0;
+}