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Last Time…. Operators Arithmetic Operators Assignment Operators Increment/Decrement Operators Relational Operators Logical Operators Expression Statements Introduction to Library Functions. Precedence of Operators. Evaluation the following Expressions: a) 4 + 7 * 6 / 3 – 5
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Last Time…. • Operators • Arithmetic Operators • Assignment Operators • Increment/Decrement Operators • Relational Operators • Logical Operators • Expression • Statements • Introduction to Library Functions
Precedence of Operators Evaluation the following Expressions: a) 4 + 7 * 6 / 3 – 5 b) ++ 23 / - 3 + 3 --
Defining constants • const Qualifier • #define directive
Automatic Type Conversion and Casts int count = 100; float avgWeight = 70F; double totalWeight = count * avgWeight; cout<<“The total weight in this room = ”<<totalWeight; Automatic Type Conversion , Compiler handles the type conversion
Static Casts int result; float a = 4.0; result = a * 3.56; <<Compiler Signals a WARNING!>> How do you cast to another type? >>Up-Cast >>Down-Cast
Implicit Type Conversion • When an operator’s operands are of different data types, C++ will automatically convert them to the same data type. • When a value is converted to a higher data type, it is said to be prompted. • To demote a value means to convert it to a lower data type.
Two Rules Rule 1: When an operator works with two values of different values of different data types, the lower-ranking value is prompted to the type of the higher-ranking value. Rule 2: When the final value of and expression is assigned to a variable, it will be converted to the data type of that variable.
Explicit Type Conversion [A type cast expression lets you manually promote or demote a value in the same way that automatic conversion takes place.]
Syntax A variable or Literal value static_cast <DataType>(Value) Data Type you wish to convert it to
How would you prevent the INTEGER DIVISION? int main() { int books, months; double booksPerMonth; cout<<“How many books do you plan to read?” cin>>books; cout<<“How many month will it take you to read them?” cin>>months; booksPerMonth = books/months; cout<<“That is”<<booksPerMonth<<“books per month.\n”; system(“pause”); return 0; }
Quiz _1 : Implement an Pseudocode Write a program that implements the following algorithm. Start Read the total hours the employee has worked, TotalHours Read the hourly rate of pay for the employee, HourlyRate GrossSalary= TotalHours* HourlyRate Tax = GrossSalary * 0.1 NetSalary = GrossSalary - Tax Display NetSalary Stop
Quiz _2:Currency [Write a program that will convert U.S. dollar amounts to Japanese yen and to euros. The conversion factors to use are 1dollar = 108.5 yen and 1 dollar = 0.8218 euros]
Library Functions Yared Semu Addis Ababa Institute of Technology April 2012
Library Functions • In C++, we make extensive use of library functions to accomplish tasks. • Mathematical Functions • IO Manipulators
Mathematical Functions The mathematical functions allow us to do mathematical operations. These operations include: • raising a number to a certain power, • computing the square root of a number, • computing the cosine of an angle, etc... . These functions are defined in the header file math.h (or cmath in standard C++). #include <cmath>
Mathematical Functions … sqrt is the name of the function that performs the square root operation. This function takes one argument of type double and returns a result of type double.
Multiple Arguments • When a function takes multiple arguments, they are separated by commas inside the parenthesis. • This statement computes 3 raised to 4.
Mathematical Functions … The function that computes the power of two numbers is : More examples of mathematical functions are:
IO Manipulators • IO Manipulators are operators used with the insertion operator (<<) to modify or manipulate the way data is displayed. • Other IO manipulators, which take arguments, are defined in the iomanip.h(or iomanipin standard C++) header file. #include <iomanip>
IO Manipulators(Example) What is the output of this program?
Example- IO Manipulators • Write a program that displays the output show below.