Intro to C++ Part 12

• How Do I Start a Program? 

1.  Identify inputs and outputs.
2. Understand what you asked for ( Ask Questions ).
3. Break the program down. // Functions
4. into steps, writing each step in pseudocode English.
5.  Replace each pseudocode step with C++ codes.

Intro to C++ Part 9

A statement

is an instruction that is executed and typically
updates some variable (called a side effect).
An expression is something that is evaluated and does not update
a variable (typically)
int x,y;
y=5;
x = (y = y+2);

What is x going to be?

Evaluate 5+2 and store 7 in y
2 Above also resulted in evaluating the y=y+2 expression, to 7.
→ store 7 in x.

It is very bad Idia to do so

Assignment Statements
In an assignment statement, first the expression on the right-hand side of the equal sign is
evaluated and then the variable on the left-hand side of the equal sign is set equal to this value.
SYNTAX
Variable = Expression;
EXAMPLES
distance = rate * time;
count = count + 2;

Intro to C++ Part 3

Programming Language history:

The original Big 4:
1954 Fortran (Formula Translator)
1958 LISP (List Processing Language)
1958 Algol (Algorithm Language)
1959 COBOL (Common Business Oriented Language)
1970s Kernighan and Richie (K&R) develop an operating system (Unix) and a language (C) targeted at efficient and low-level applications.
1983 Stroustrup creates C++,

  

Intro to C++ Part 2

What is Programming? 

Simply writing codes; however, the codes should have a correct format:

• Readability - Writeability 
• Documentation: Header comments for each module,
• meaningful inline comments for code 
• Correctness 

A C++ Sample code with a fine format:

#include <iostream> // Including Input Output library

using namespace std; // using namespace" is a command, and "std" is a little something called a library. "std" stands for "standard".

int main() // Main function
{
    cout << "Hello world!" << endl; // Will be print Hello World on screen. 
    return 0;// Main function always return 0.
}