CSC 1060: Data Types and Variables

CSC 1060: Data Types and Variables

• Objectives: Understand and differentiate between fundamental data types in C++, declare & initialize variables, explain the data type concept, correctly declare variables in C++, apply appropriate naming conventions, and understand the importance of naming conventions.

• Agenda (Week 3):

  • Data Types & Variables
  • Declaration of a Variable
  • Naming Conventions for Variables
  • Coding Standards for Variables
  • Operators
  • Assignment
  • Solve Problem with Code
  • Type Conversation - and std::string
  • String common operators and functions
  • TODO & Resources for Help

• Fundamental Data Types in C++: int, float, double, char, bool

• String: Not a fundamental data type; part of C++ as std::string. Requires #include

• C++ Variable Declaration:

  • Data Type: Specifies the amount of storage and operations.
  • Name: Identifies the variable in a program; starts with a lowercase letter.
  • Value: Assigned into memory. Format: dataType name = value;

• C++ Rules & Standards (Variable Naming): Example variations: first-place, FirstPlace, first_place, 1stPlace, firstPlace, place, rankedlst

• C++ Declaring Variables: Examples provided as placeholders to be filled in:

  • = 0; // number of letters in word
  • = 0; // first name initial
  • = 0; // balance in bank account
  • = 0; // overall grade percent

• Assignment Statements:

  • Value assigned to variable leftVariable = rightValue;
  • Data types of left and right values should match for type safety.
  • Left variable must be declared before use (and cannot be a constant).
  • Right value can be an expression, formula, or another variable.

• Operators (C++):

  • Arithmetic: PEMMDAS ((), *, %, /, +, -)
  • Order of Operations (PEMDAS)
  • Exponent operator in C++
  • Modulus (%): remainder from division
  • Floating-point Division (/): 5/2.0
  • Integer Division (/): 5/2

• Solve Problem #1 with Code:

  • Single fair ticket: $8
  • Family pass: $25 more than half the ticket price. Calculate.

• Type Conversion (C++):

  • Implicit: Automatically occurs when copying to a compatible type.
  • Explicit (Casting): Needed for conversions involving data loss or different interpretations (e.g., int to float conversion).

• C++ std::string:

  • Sequence of characters; standardized data type.
  • No C-style strings (char[] or char*) – use std::string.
  • Stored contiguously in memory.
  • Indexed (0-based).

• std::string Object (Variable):

  • #include <string>
  • Create empty string: std::string name;
  • Create string from literal: std::string firstName = "Julie"; or std::string firstName("Julie");

• Common std::string Operations:

  • Assignment (=): assigns values
  • Concatenation (+): adds strings together
  • Subscript ([]): getting/setting characters at a particular index

• Common std::string Member Functions:

  • size() or length(): returns the number of characters in a string.
  • at(index): returns a character at a specified index.
  • find(char): searches for a character
  • substr(pos, len): selects part of the string.

• Common std::string Functions (Conversion):

  • std::to_string(var): converts various types (ints, floats, doubles) to a string.
  • std::stoi(str), std::stof(str), std::stod(str): converts strings to integers, floats, and doubles respectively.

• Solve Problem #2 with Code:

• Given "Red Rocks", reverse the string to "Rocks Red"

• Review Exercises: Complete multiple-choice questions 1-10.

• TODO: Complete week 2 content module in D2L to 100%.

• Post: Weekly discussion question and research solution to D2L

• Next: Week 3 prework starts Friday 1/26 8AM

• Help:

  • Student Office Hours: By appointment or drop-in.
  • Email: [email protected]
  • Tutoring:
    • On-campus tutoring: Link provided
    • 24/7 Online Tutoring: D2L content > Resources for Help