#ece244

Big picture: Basic Computer Structure

C++ Program -> Compilation -> Machine Code

• saved in storage device (.cpp file and the compiled file, i.e. executable file)
• when running the program, we take the compiled file (executable) and put it in RAM
• CPU fetches data from RAM, executes the executable (performs operations) and then saves output data to RAM
  • if needed, communicates interacts with IO before saving output to RAM

OS

• provides an interface between applications and hardware (e.g., web browser, vs code, video game, C++ program, etc.)

simple C++ program

#include <iostream>
using namespace std;
int main(void) {
	int num1, num2;
	cout << "Enter two numbers" << endl; // string INTO cout, hence <<
	cin >> num1 >> num2; //operator INTO variable, hence >>
	cout << "The sum is " << num1 + num2 << "!" << endl;
	return 0;
}

data types in C++

1. Integers: numbers without decimal places
   1. int = 4 bytes (32 bits) for this course we will use int
   2. long >= 32 bits
      1. sizeof(long) should be 64 bits usually
2. Real numbers numbers that may contain decimal places
   1. double = 64 bits for this course we will use double
   2. float = 32 bits
   3. long double >= 64 bits
3. Characters: 'A', 'a', '$', '\n'
   1. char = 1 byte (8 bits)
4. boolean
   1. bool = 1 byte
5. Arrays to store multiple data elements of the same data type:
   int arr[7] = {70, 2, 3, 4, 5, 6, 7};
arr[0] = 1

strings in C

no particular data type; array of characters
char h[] = "hello"; is stored as 'h', 'e', 'l', 'l', 'o', '\0'
In C, we had to #include <string.h> to get access to functions like strlen, strcpy, strcat, etc.

strings in C++

In C++, we have a string "class" that allows you to create a string type variable.
You can use operations on these strings like +, ==, and !=.

// sees if entered course department and code are ECE244
#include <string>
#include <iostream>
using namespace std;

int main(void) {
	string courseDep, courseCode;
	
	cout << "Enter course code " << endl;
	cin >> courseDep >> courseCode;
	string combined = courseDep + courseCode;
	if (combined == "ECE244") {
		cout << "This is programming fundamentals" << endl;
	} else {
		cout << "This course is not programming fundamentals" << endl;
	}
	
	return 0;
}

Expressions that still apply in C++:

• if () {}
• for () {}, while () {}, do while
• Operations
  • arithmetic
  • relational
  • logical