Programming
Preprocessor Directives
#include <iostream>. In a C++ program, statements that begin with the symbol # are called preprocessor directives. These statements are processed by a program called preprocessor.
Arithmetic operators
+ Addition - Subtraction or negation * Multiplication / Division % Modulus or remainder
Assignment statements
...
Function Main
A C++ program is a collection of functions, one of which is the function main. All C++ programs require a function main.
Output devices
A monitor, printer, and secondary storage.
Compiler
A program that translates instructions written in a high-level language into the equivalent machine language.
Reserved Words
A second category of tokens is reserved word symbols. Some of the reserved word symbols include the following: int, float, double, char, const, void, return Reserved words are also called keywords. The letters that make up a reserved word are always lowercase. Each reserved word is considered to be a single symbol. Furthermore, reserved words cannot be redefined within any program.
Programming language
A set of rules, symbols, and special words. Special symbols, words, and syntax rules.
Identifiers
A third category of tokens is identifiers. Identifiers are names of variables, constants, and functions. Identifier must begin with a letter or underscore and must consists of letters, digits, and the underscore character (_), no other symbols are permitted to form an identifier. Some identifiers are predefined; two predefined identifiers that you will encounter frequently are cout and cin. Unlike reserved words, predefined identifiers can be redefined, but it would not be wise to do so.
<iostream>
scientific
<iomanip>
setfill
<iomanip>
setprecision
<iomanip>
setprecision, setw, setfill
<iomanip>
setw
<iostream>
showpoint
int main ()
{ }
Data type rules
• You can use the operators +, -, *, and / with both integral and floatingpoint data types. These operators work with integral and floating-point data the same way as you learned in a college algebra course. • When you use / with the integral data type, it gives the quotient in ordinary division. That is, integral division truncates any fractional part; there is no rounding. • You use % with only the integral data type, to find the remainder in ordinary division.
User readability
Formatting
Structured Programming
Functions
Function arguments/parameters
Header/library<cmath> Function Pow(x,y); Argument (x,y);
Expressions
Integral expression Floating-point Mixed expressions
Machine Language
Is the most basic language of a computer, the machine language, provides program instructions in bits.
Fail state
Is when the wrong data type is inputted.
Structured Programming
Iteration
Order of precedence
Left to right ( ) Left to right * / % Left to right + -
Logic errors
Logic errors are when the answer does not meet the expectations. Logic errors are typically not caught by the compiler. Example 1+1=5
Long
Long is used to represent integers between -9223372036854775808 9223372036854775807.
Block comment
Multiple-line comments are enclosed between /* and */. The compiler ignores anything that appears between /* and */.
Predefined Function
Predefined or standard functions, are already written functions when it is activated, or executed, it accomplishes something.
Code readability
Proper indentation can show the natural grouping and subordination of statements. If your program is properly indented, you can spot and fix errors quickly.
Run-time errors
Run-time errors are given when the code cannot be executed at that particular moment. Example a division by 0.
Structured Programming
Selection
Structured Programming
Sequence
Single line comment
Single-line comments begin with // and can be placed anywhere in the line. Everything encountered in that line after // is ignored by the compiler.
Software
Software are programs written to perform specific tasks. There are two types of programs: system programs and application programs. System programs control the computer. Application programs perform a specific task. Word processors, spreadsheets, and games are examples of application programs.
Predefined identifiers - cin and cout
Some identifiers are predefined; two predefined identifiers that you will encounter frequently are cout and cin. Unlike reserved words, predefined identifiers can be redefined, but it would not be wise to do so.
Syntax errors
Syntax errors are given when the rules of the language are used incorrectly. Errors in syntax are detected during compilation. Example missing ";" or ">>".
Short
The Short data type is used to represent integers between -32,768 and 32,767, or numbers without a decimal part.
Source Code
The code of a program written in a high-level language.
Bool
The data type bool has only two values: true and false. True and false are reserved words. The identifier true is set to 1, and the identifier false is set to 0
Char
The data type char is mainly used to represent single characters—that is, letters, digits, and special symbols. Thus, the char data type can represent every key on your keyboard. When using the char data type, you enclose each character represented within single quotation marks.
Double
The data type double is to represent any decimal number between -1.7*E308 and 1.7*E308 . The memory allocated is eight bytes.
Float
The data type float is used to represent any decimal number between -3.4*E38 and 3.4*E38. The memory allocated is four bytes.
Int
The int data type is used to represent integers between -2,147,483,648 and 2,147,483,647, or numbers without a decimal part.
Input devices
The keyboard, mouse, scanner, camera, and secondary storage.
Object Code
The machine language version of the high-level language program.
Using namespace std;
The namespace mechanism is a feature ofANSI/ISO Standard C++. using namespace std;
Operating System
The operating system handles the overall activity of the computer and provides services. Some of these services include memory management, input/output activities, and storage management.
Concatenate
The operator + can be used to concatenate two values of the type string. width + length outputs WitLen.
Data Types
int short long char bool unsigned float double
Extraction
int main()
<iostream>
left
Insertion
<<
Extraction
>>
ASCII
ASCII is a patterns of seven bits that represent in computers the upper and lowercase letters of the English alphabet, punctuation symbols, the digits 0 through 9, and certain control information such as line feeds, carriage returns, and tabs
Program Planning
Algorithm Get.... Do.... Print Input....Process....Output Pseudo code
Literals
Are of the data type string and are declare with "quotations marks"
Case sensitive
C++ is case sensitive—uppercase and lowercase letters are considered different. Thus, the identifier Number is not the same as the identifier number or NUMBER.
Casting data types
Casting data types means to converter a floating-point (decimal) number to an integer by simply dropping the decimal part of the floating-point number.
Cin
Cin (pronounced ''see-in''), which stands for common input (Keyboard).
Const
Const is a memory location whose content is not allowed to change during program execution. In C++, const is a reserved word. Count must be initialized and declared all in one statement because from this statement on the compiler will reject any attempt to change the value.
Cout
Cout (pronounced ''see-out''), which stands for common output (Monitor).
Header file (#include < > )
Every library has a name and is referred to by a header file. #include <iostream>
Declarations
Declaration statements are used to declare things, such as variables.
Structured Programming
Dividing a problem into smaller subproblems is called structured design. Each subproblem is then analyzed, and a solution is obtained to solve the subproblem. The solutions to all of the subproblems are then combined to solve the overall problem. This process of implementing a structured design is called structured programming.
Special Symbols
The smallest individual unit of a program written in any language is called a token. C++'s tokens are divided into special symbols, word symbols, and identifiers. Following are some of the special symbols: + Addition - Subtraction * Multiplication / Division % Modulus/Remainder . Decimal point and regular expression operator. ; End of statement. , Commas are used to separate items in a list. = Means assign what is on the right to the left of the symbol. <= Item on the left is less than or equal to the item on the right of the symbol. >= Item on the left is greater than or equal to the item on the right of the symbol. == Item on the right equals to the item on the left of the symbol. != Item on the right not equals to the item on the left of the symbol.
return 0;
The statement return 0; must be included in the function main and must be the last statement. For now, think of this statement as the end-of-program statement. In C++, return is a reserved word.
Syntax
The syntax rules of a language tell what is legal and what is not legal.
Initialization
There are two ways to initialize a variable: by using the assignment statement and by using a read statement (common input).
whitespace
Whitespaces include blanks, tabs, and newline characters. Whitespaces are nonprintable.
Escape Sequence
\t Tab \n Next line \\ Backslash \" Double quotations \' Single quotations \b Backspace \r Beginning of current line
Extraction
cin
Insertion
cout
fixed
cout << fixed;
ostreamVar << left;
cout << left;
ostreamVar << right;
cout << right;
ostreamVar << setfill(ch);
cout << setfill('#');
setprecision(n)
cout << setprecision(#);
setw
cout << setw(#) << x << endl;
unsetf
cout.unsetf(ios::fixed);
ostreamVar.unsetf(ios::left);
cout.unsetf(ios::left);
<iostream>
endl
<iostream>
endl, fixed, showpoint, scientific, left
<iostream>
fixed