Programming Abstraction in C++ # 01. Overview of C++

1.Overview of C++

1.2 The history of C++

📌Days before C++

People are using machine language which reflects the design of the hardware rather than the needs of programmers.

📌High-level programming language

The first high-level programming language is called FORTRAN(formula translation) which resembles the mathematical formulas into machine language.

📌Object-oriented paradigm

Before it, it is procedural paradigm represented by C. C++ is built of C and shifts the paradigm.

1.3. The compilation process

You should be aware of the following concepts:

• source file
• compiler
• object file
• executable file
• libraries
• linker

1.4. The structure of a C++ program

1.6. Data Types

📌Integer types

If long int + int, the result is int which will promote the precision.

📌Floating-point types

Floating-point with scientific notation.

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double num = 2.9979E+8;

E+8 means ${10}^8$

📌Characters

ASCII stands for American Standard Code for Information Interchange.

The row stands for 10, col stands for 1. Therefore A is 65 = 10 * 6 + 5 * 1

📌Strings

The string is not a primitive type in C++ while it is, in fact, a library type(history artifact with C). In this book, we uses the string library wherever possible.

1.7. Expressions

📌Mixing types in an expression

The type-conversion is with the following order:

For example:

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double num = 0;
num += 1;
// num now is 1.0

📌Truncation

It is the operation of discarding a decimal fraction.

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int result = 9 / 4;  //result is 2

📌Type casts

type cast in C++:

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quotient = double(num) / den;

type cast in C#:

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quotient = (double) num / den;

📌Embedded Assignment

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int x, y, z;
z = (x = 6) + (y = 7);

While we don't recommend these kinds of operation which are difficult to understand.

📌Multiple Assignment

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int n1, n2, n3;
n1 = n2 = n3 = 0;

📌Increment and Decrement Operator

The difference between ++x and x++.

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{
    cout << *first << endl;
    *at = *first;
    at++;
    first++;
}

is equivalent to the following:

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{
    cout << *first << endl;
    *at++ = *first++;
}

1.8. Statements

📌Predicate Functions

Functions like isVowel() or isAlphabet are called predicate functions.