XB40011: Computer Programming
ZyBooks Academic Year 2020
INDEX
Chapter 8 : Introduction to C++ ........................................................................................................................1
Chapter 9 : Variables / assignments ..................................................................................................................2
Chapter 10 : Branches .......................................................................................................................................3
Chapter 11: Loops .............................................................................................................................................5
Chapter 12 : Array and Vectors .........................................................................................................................5
Chapter 13 : Streams .........................................................................................................................................6
Chapter 14 : Exceptions and Assertions ............................................................................................................7
Chapter 15 : User-Defined Functions ...............................................................................................................8
Chapter 16 : Recursion ....................................................................................................................................10
Chapter 17 : Objects and Classes ....................................................................................................................10
Chapter 18: Pointers ........................................................................................................................................12
Chapter 8 : Introduction to C++
➤8.1 Programming basics
• A program starts in main(){} and ‘return 0’ ends the program
• Each statement ends with a semicolon ‘;’
• Each variable must be initialized
• An input is commonly gotten from a users input on the keyboard or files.
• cin provides a standard input stream, this is followed by ‘>>’
• cout provides a standard output stream, this is followed by ‘<<’
• In order to output text you simply type the desired text in between double quotes “ ”
• The statement cout << endl starts a newline. The newline character ‘\n’ also puts out a new line
• For outputting multiple things you can split the items up with <<
➤8.2 Comments and whitespace
• Text the programmer adds to a code for a better understanding but ignored by the compiler.
• Single-line comment starts with ‘//’ followed by the desired text
• Multi-line comment (a.k.a. block comment) starts with ‘/*’ and ends with ‘*/’ with text in between
• Refers to blank spaces between items within a statement and blank lines between statements.
• It’s good practice to separate different parts of code with whitespace to make it more readable.
• Indent lines the same amount, align items and use a single space before and after operators.
➤8.3 Errors and warnings
• Syntax error/compile-time error: To violate a programming language's rules on how symbols can be
combined to create a program. A compiler generates a message when encountering such an error, telling
the programmer where and what is missing.
• But compiler error messages can be wrong, as it gives a best guess about the problem.
• Always focus on the first error first since this error could’ve caused the following errors.
• Logic error/bug: An error that is not picked up by the compiler since it’s technically correct but not in
such way the programmer meant. A warning indicates a possible logic error.
• -Wall will give the programmer more possible warnings, using this is considered good practice.
➤8.4 Computers and programs in general
• Bits are either 0’s or 1’s
• Back in the day people would connect switches to form circuits. Circuits called processors would process
instructions, which were stored in memory(a circuit that stores 0’s and 1’s).
• Instructions consists of 3 parts: location, what to do and where to store the result
• A sequence of instructions is called a program, application or app.
• High-level languages were created, allowing programmers to use ‘normal’ characters instead of just 0’s
and 1’s. Compilers would transfer this to executable programs(0’s and 1’s).
, Chapter 9 : Variables / assignments
➤9.1&9.2 Variables and assignments
• Variable: A named item used to hold a value.
• Assignment: Assigns a variable with a value, the variable keeps that value until it’s changed.
• Variable declaration: A statement that declares a new variable, specifying the its name and type.
• The processor writes the assigned value into the variable's memory location.
• Assignment statement: Assigns the variable with a value.
• You can also directly assign a value to a variable while declaring it.
• A common error is to read a variable before declaring it or writing the assignment in reverse.
➤9.3 Identifiers
• Identifier: A name created by a programmer for an item like a variable or function.
• An identifier must:
- Be a sequence of letters, underscores or digits
- Always begin with a letter or underscore
• It’s case sensitive and the identifier can’t have the same name as a reserved word/key word.
• It’s good practice to give it meaningful names and to minimize use of abbreviations.
➤9.4&9.5 Arithmetic expression
• Expression: A combination of items that evaluates to a value.
• A literal is a specific value. Operators are symbols with a built-in calculation function.
• The precedence rules of expressions work just like the math rules.
• It’s considered good practice to use spaces between the variables and operators.
• Compound operators are used as a shorthand way to update the variable. E.g. ‘+=’
➤9.7&9.8 Floating-point numbers (double)
• Type ‘double’ stores a floating-point number. A floating-point literal is a number with a fractional
part. It’s considered good practice to have a non-zero digit before the decimal point.
• The variable type should be chosen wisely, looking at which type you will use.
• Dividing a nonzero floating-point number by zero results in ‘inf’ or ‘-inf’ standing for infinity.
• If the numbers are both 0’s, the compiler will put out ‘nan’, since it’s not a number.
• Scientific notation is useful if the number is much bigger or much smaller than usual. It’s considered
good practice to have the leading digit to be non-zero.
➤9.9 Constant variables
• It’s good practice to minimize the use of literal numbers in code.
• Some variable are meant to be constant, so if you use the keyword ‘const’ the compiler will give an error
when the programmer wants to change the variable later.
➤9.10 Using math functions
• Standard math libraries like ‘cmath’ or ‘math.h’ allow the
programmer to use math functions.
• Such functions take arguments that appear in ().
• It’s common that an argument of a function call also has a
function call itself.
Commonly used math functions
➤9.11 Integer division and modulo
• When operands are integers, the division operator does not generate the fraction.
• For integer division, the second operand of / or % must never be 0, because division by 0 is
mathematically undefined it will cause an error.
• The modulo operator ‘%’ gives the remainder of an integer division.
➤9.12 Type conversions
• A type conversion changes one type to another. An automatic one is known as implicit conversion.
• For arithmetic operators both operands will become doubles. Whereas for assignments, the right side will
be converted to the type of the left side.
ZyBooks Academic Year 2020
INDEX
Chapter 8 : Introduction to C++ ........................................................................................................................1
Chapter 9 : Variables / assignments ..................................................................................................................2
Chapter 10 : Branches .......................................................................................................................................3
Chapter 11: Loops .............................................................................................................................................5
Chapter 12 : Array and Vectors .........................................................................................................................5
Chapter 13 : Streams .........................................................................................................................................6
Chapter 14 : Exceptions and Assertions ............................................................................................................7
Chapter 15 : User-Defined Functions ...............................................................................................................8
Chapter 16 : Recursion ....................................................................................................................................10
Chapter 17 : Objects and Classes ....................................................................................................................10
Chapter 18: Pointers ........................................................................................................................................12
Chapter 8 : Introduction to C++
➤8.1 Programming basics
• A program starts in main(){} and ‘return 0’ ends the program
• Each statement ends with a semicolon ‘;’
• Each variable must be initialized
• An input is commonly gotten from a users input on the keyboard or files.
• cin provides a standard input stream, this is followed by ‘>>’
• cout provides a standard output stream, this is followed by ‘<<’
• In order to output text you simply type the desired text in between double quotes “ ”
• The statement cout << endl starts a newline. The newline character ‘\n’ also puts out a new line
• For outputting multiple things you can split the items up with <<
➤8.2 Comments and whitespace
• Text the programmer adds to a code for a better understanding but ignored by the compiler.
• Single-line comment starts with ‘//’ followed by the desired text
• Multi-line comment (a.k.a. block comment) starts with ‘/*’ and ends with ‘*/’ with text in between
• Refers to blank spaces between items within a statement and blank lines between statements.
• It’s good practice to separate different parts of code with whitespace to make it more readable.
• Indent lines the same amount, align items and use a single space before and after operators.
➤8.3 Errors and warnings
• Syntax error/compile-time error: To violate a programming language's rules on how symbols can be
combined to create a program. A compiler generates a message when encountering such an error, telling
the programmer where and what is missing.
• But compiler error messages can be wrong, as it gives a best guess about the problem.
• Always focus on the first error first since this error could’ve caused the following errors.
• Logic error/bug: An error that is not picked up by the compiler since it’s technically correct but not in
such way the programmer meant. A warning indicates a possible logic error.
• -Wall will give the programmer more possible warnings, using this is considered good practice.
➤8.4 Computers and programs in general
• Bits are either 0’s or 1’s
• Back in the day people would connect switches to form circuits. Circuits called processors would process
instructions, which were stored in memory(a circuit that stores 0’s and 1’s).
• Instructions consists of 3 parts: location, what to do and where to store the result
• A sequence of instructions is called a program, application or app.
• High-level languages were created, allowing programmers to use ‘normal’ characters instead of just 0’s
and 1’s. Compilers would transfer this to executable programs(0’s and 1’s).
, Chapter 9 : Variables / assignments
➤9.1&9.2 Variables and assignments
• Variable: A named item used to hold a value.
• Assignment: Assigns a variable with a value, the variable keeps that value until it’s changed.
• Variable declaration: A statement that declares a new variable, specifying the its name and type.
• The processor writes the assigned value into the variable's memory location.
• Assignment statement: Assigns the variable with a value.
• You can also directly assign a value to a variable while declaring it.
• A common error is to read a variable before declaring it or writing the assignment in reverse.
➤9.3 Identifiers
• Identifier: A name created by a programmer for an item like a variable or function.
• An identifier must:
- Be a sequence of letters, underscores or digits
- Always begin with a letter or underscore
• It’s case sensitive and the identifier can’t have the same name as a reserved word/key word.
• It’s good practice to give it meaningful names and to minimize use of abbreviations.
➤9.4&9.5 Arithmetic expression
• Expression: A combination of items that evaluates to a value.
• A literal is a specific value. Operators are symbols with a built-in calculation function.
• The precedence rules of expressions work just like the math rules.
• It’s considered good practice to use spaces between the variables and operators.
• Compound operators are used as a shorthand way to update the variable. E.g. ‘+=’
➤9.7&9.8 Floating-point numbers (double)
• Type ‘double’ stores a floating-point number. A floating-point literal is a number with a fractional
part. It’s considered good practice to have a non-zero digit before the decimal point.
• The variable type should be chosen wisely, looking at which type you will use.
• Dividing a nonzero floating-point number by zero results in ‘inf’ or ‘-inf’ standing for infinity.
• If the numbers are both 0’s, the compiler will put out ‘nan’, since it’s not a number.
• Scientific notation is useful if the number is much bigger or much smaller than usual. It’s considered
good practice to have the leading digit to be non-zero.
➤9.9 Constant variables
• It’s good practice to minimize the use of literal numbers in code.
• Some variable are meant to be constant, so if you use the keyword ‘const’ the compiler will give an error
when the programmer wants to change the variable later.
➤9.10 Using math functions
• Standard math libraries like ‘cmath’ or ‘math.h’ allow the
programmer to use math functions.
• Such functions take arguments that appear in ().
• It’s common that an argument of a function call also has a
function call itself.
Commonly used math functions
➤9.11 Integer division and modulo
• When operands are integers, the division operator does not generate the fraction.
• For integer division, the second operand of / or % must never be 0, because division by 0 is
mathematically undefined it will cause an error.
• The modulo operator ‘%’ gives the remainder of an integer division.
➤9.12 Type conversions
• A type conversion changes one type to another. An automatic one is known as implicit conversion.
• For arithmetic operators both operands will become doubles. Whereas for assignments, the right side will
be converted to the type of the left side.
