1 files changed, 38 insertions, 0 deletions
diff --git a/4p9.cpp b/4p9.cpp
new file mode 100644
index 0000000..101f1c9
--- /dev/null
+++ b/4p9.cpp
@@ -0,0 +1,38 @@
+#include <iostream>
+
+/*
+ *
+ * 4.9
+ *
+ *
+ */
+
+int main () {
+	// True if:
+	// the address pointed to isnt null
+	// the first character isnt a null character
+
+	// We can test this by making a string literal, for exmple "Hello world"
+	// We can also test by putting the null character \0 in the string literal
+	// And we can also test by pointing cp at nullptr
+	int choice;
+	const char *hw = "Hello world!";
+	const char *np = nullptr;
+	const char nc = '\0';
+	const char *cp;
+	std::cout << "1: Hello World | 2: nullptr | 3: null character" << std::endl;
+	if(std::cin >> choice) {} else { return -1; }
+	
+	if(choice == 1) { cp = hw; }
+	else if(choice == 2) { cp = np; }
+	else if(choice == 3) { cp = &nc; }
+	else { return -1; }
+	
+	if (cp && *cp) {
+		std::cout << "valid" << std::endl;
+	} else {
+		std::cout << "not valid" << std::endl;
+	}
+
+	return 0;
+}