more

8 files changed, 337 insertions, 0 deletions

diff --git a/3p27.cpp b/3p27.cpp
new file mode 100644
index 0000000..de4f9d2
--- /dev/null
+++ b/3p27.cpp
@@ -0,0 +1,37 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.27
+ *
+ *
+ */
+
+using std::string;
+using std::cout;
+using std::cin;
+using std::cerr;
+using std::clog;
+using std::endl;
+using std::vector;
+
+int text_size() {
+
+	return 9900;
+}
+
+int main () {
+
+	//unsigned buf_size = 1024;
+	//int ia1[buf_size]; // illegal
+	int ia2[4 * 7 - 14]; // legal
+	//int ia3[text_size()]; // illegal, would be legal if text_size returned constexpr
+	//char st[11] = "fundamental"; // illegal
+
+	ia2[0] = 1;
+	cout << ia2[0] << endl;
+	return 0;
+}
diff --git a/3p28.cpp b/3p28.cpp
new file mode 100644
index 0000000..14f617a
--- /dev/null
+++ b/3p28.cpp
@@ -0,0 +1,30 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.28
+ *
+ *
+ */
+
+using std::string;
+using std::cout;
+using std::cin;
+using std::cerr;
+using std::clog;
+using std::endl;
+using std::vector;
+
+string sa[10]; // Default initialized strings
+int ia[10]; // ints with 0
+int main() {
+
+	string sa2[10]; // Default initialized strings
+	//int	ia2[10]; // Unititialized, UB
+
+	cout << sa[0] << "|" << ia[0] << "|" << sa2[0] << endl;
+	return 0;
+}
diff --git a/3p29.cpp b/3p29.cpp
new file mode 100644
index 0000000..d219ef1
--- /dev/null
+++ b/3p29.cpp
@@ -0,0 +1,31 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.29
+ *
+ *
+ */
+
+using std::string;
+using std::cout;
+using std::cin;
+using std::cerr;
+using std::clog;
+using std::endl;
+using std::vector;
+
+int main() {
+
+	/*
+	  - We need to know the size of an array when we create it
+	  - We cannot initialize an array with another array and we cannot assign an array to another
+	  - We cannot increase an array's size like we can with vectors.
+	  - character arrays need space for the null character
+
+	 */
+	return 0;
+}
diff --git a/3p30.cpp b/3p30.cpp
new file mode 100644
index 0000000..68d4cdd
--- /dev/null
+++ b/3p30.cpp
@@ -0,0 +1,65 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.30
+ *
+ *
+ */
+
+using std::string;
+using std::cout;
+using std::cin;
+using std::cerr;
+using std::clog;
+using std::endl;
+using std::vector;
+
+int main() {
+	/*
+	constexpr size_t array_size = 10;
+	int ia[array_size];
+	for (size_t ix = 1; ix <= array_size; ++ix) {
+		ia[ix] = ix;
+	}
+
+	In the for loop:
+	ix should start at 0 rather than 1. Because when we use subscripts it starts at 0.
+	In this case, if we were to start with '1' then the first element in the array would remain uninitialized.
+
+	ix should also not be compared to array sized using <=
+	array_size only tells us how many elements the array has, but when using subscripts we start at 0, so this means
+	we would need to compare to array_size-1 or use just the '<' operator, because then we also check at array_size-1
+
+	If we want to nitpick about the requirements of what the program is supposed to do we could change even more.
+	Maybe we want to start at 1 and get an array of 1 - 10?
+	*/
+
+	// Fixed version here, fills array with 0 - 9
+	constexpr size_t array_size = 10;
+	int ia[array_size];
+	for (size_t ix = 0; ix < array_size; ++ix) {
+		ia[ix] = ix;
+	}
+
+	// Same program but if we wanted the array to be from 1 - 10
+	constexpr size_t array_size2 = 10;
+	int ia2[array_size2];
+	for (size_t ix2 = 0; ix2 < array_size2; ++ix2) {
+		ia2[ix2] = ix2 + 1;
+	}
+
+	for(auto i : ia) {
+		cout << i << endl;
+	}
+	
+	cout << endl;
+	for(auto i : ia2) {
+		cout << i << endl;
+	}
+	
+	return 0;
+}
diff --git a/3p31.cpp b/3p31.cpp
new file mode 100644
index 0000000..0e7970b
--- /dev/null
+++ b/3p31.cpp
@@ -0,0 +1,40 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.31
+ *
+ * I mean this was really easy because i just remembered what
+ * i'd already seen in the last exercise...
+ * I made one more like the one in the book and one that's
+ * a little bit more simpler. Not sure how 'correct' the simpler
+ * version is. Who knows...
+ */
+
+int main () {
+
+	constexpr size_t ArraySize = 10;
+	int MyArray[ArraySize];
+	for(size_t Index = 0 ; Index != ArraySize ; ++Index) {
+		MyArray[Index] = Index;
+	}
+
+	int MyArray2[10];
+	for(int Index = 0 ; Index != 10 ; ++Index) {
+		MyArray2[Index] = Index;
+	}
+
+	for(auto i : MyArray) {
+		std::cout << i << std::endl;
+	}
+
+	std::cout << std::endl;
+	for(auto i : MyArray2) {
+		std::cout << i << std::endl;
+	}
+	
+	return 0;
+}
diff --git a/3p32.cpp b/3p32.cpp
new file mode 100644
index 0000000..2510e21
--- /dev/null
+++ b/3p32.cpp
@@ -0,0 +1,59 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.32
+ *
+ * 
+ */
+
+int main () {
+
+	constexpr size_t ArraySize = 10;
+	int MyArray[ArraySize];
+	int MyArray2[ArraySize];
+	for(size_t Index = 0 ; Index != ArraySize ; ++Index) {
+		MyArray[Index] = Index;
+	}
+
+	for(size_t Index = 0 ; Index != 10 ; ++Index) {
+		MyArray2[Index] = MyArray[Index];
+	}
+
+	for(auto i : MyArray) {
+		std::cout << i << std::endl;
+	}
+
+	std::cout << std::endl;
+	for(auto i : MyArray2) {
+		std::cout << i << std::endl;
+	}
+	
+	std::cout << std::endl;
+
+	// Vector version
+	size_t VecSize = 10;
+	std::vector<int> MyVec;
+	std::vector<int> MyVec2;
+	for(size_t Index = 0 ; Index != VecSize ; ++Index) {
+		MyVec.push_back(Index);
+	}
+
+	MyVec2 = MyVec;
+	// If we wanted to we could also initialize MyVec2 here instead of above
+	// std::vector<int> MyVec2 = MyVec;
+	
+	for(auto i : MyVec) {
+		std::cout << i << std::endl;
+	}
+
+	std::cout << std::endl;
+	for(auto i : MyVec2) {
+		std::cout << i << std::endl;
+	}
+	
+	return 0;
+}
diff --git a/3p33.cpp b/3p33.cpp
new file mode 100644
index 0000000..96d0105
--- /dev/null
+++ b/3p33.cpp
@@ -0,0 +1,43 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 3.33
+ *
+ *
+ */
+
+using std::string;
+using std::cout;
+using std::cin;
+using std::cerr;
+using std::clog;
+using std::endl;
+using std::vector;
+int main () {
+	/*
+	  Because we assume all score clusters to start at a value of 0 when we increment,
+	  we need to initialize them with 0 because if we did not then each array element
+	  could have any value because it is uninitialized.
+
+	  When we compile the program and run, we can see the uninitialized values get
+	  printed.
+	 */
+	unsigned scores[11];
+	unsigned grade;
+	while (cin >> grade) {
+		if (grade <= 100) {
+			++scores[grade/10];
+		}
+	}
+
+	for (auto i : scores) {
+		cout << i << " ";
+	}
+	
+	cout << endl;
+	return 0;
+}
diff --git a/array-test.cpp b/array-test.cpp
new file mode 100644
index 0000000..dd58435
--- /dev/null
+++ b/array-test.cpp
@@ -0,0 +1,32 @@
+#include <iostream>
+#include <vector>
+#include "sales_data.hpp"
+#include "sales_item.hpp"
+
+/*
+ *
+ * 
+ *
+ *
+ */
+
+using std::string;
+using std::cout;
+using std::cin;
+using std::cerr;
+using std::clog;
+using std::endl;
+using std::vector;
+int main () {
+
+	constexpr int isz = 10;
+	int fff[isz];
+	fff[0] = 304234;
+	cout << fff[0] << endl;
+
+	int arr[] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100};
+	int (*arr_p)[10] = &arr;
+	cout << &(*arr_p)[2] << " " << &arr[2] << endl;
+	// This syntax is crazy!
+	return 0;
+}