Operators and Expressions Chapter 2 Operators and Expressions

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Operators Operation Operator Rank Addition + 2 Subtraction - 2 Multiplication * 1 Division / 1

More on operators Unary – one operand Binary – two operands Ternary – one of two possible results

Addition When you want to add 5 and 10 5+10 using variables: num1 = 5; total = num1 + num2;

Addition How to use: int student1 = 100; int student2 = 95; int sum; sum = student1+student2+student3; Console.WriteLine(“s1 = {0}, s2 = {1}, s3 = {2}”, student1, student2, student3); Console.Writeline(“sum = “ + sum);

Program style // declare section int student1; int student2; int sum; // input section student1=100; student2=95; student3=96; // calculate section sum = student1+student2+student3; // results section Console.WriteLine(“s1 = {0}, s2 = {1}, s3 = {2}”, student1, student2, student3); Console.Writeline(“sum = “ + sum);

Subtraction double salary = 255.32; double benefits = 26.66; double netsal; netsal = salary – benefits; Console.WriteLine(“Sal={0}, Ben={1}, Net={2}”, salary, benefits, netsal);

Multiplication double grade=4.0; double credits=3.0; double qualpts; Console.WriteLine(“With a grade of {0}, and {1} credits, you earned {2} QP”, grade, credits, grade * credits);

Division As with the other operators, merely place it between two numeric variables int hrsofsleep; int hrsofstudy; double grade = hrsofstudy / hrsofsleep;

Allowing User Input double grade; grade = double.Parse(Console.ReadLine()); (Or int or decimal ) Console.Write(“Please enter numeric Grade ”);

Formatting Output When you want to print money without $: netsal = 2600.4566666 Console.WriteLine(“Net Salary {0:N2}”, netsal) Result: Net Salary 2,600.45 Console.WriteLine(“Net Salary {0:C}”, netsal) Result: Net Salary $2,600.45

Increment and Decrement int age = 2; age = age + 2; what is the value of age? old = age++; (called postfix) same as old=age; and then age=age+1 old=++age; Same as age=age+1; and then old=age;

Ternary Operator exp1 ? exp2 : exp3 If exp1 is true, do exp2 If exp1 is false, do exp3