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Homework 3.2 ♫ What is the difference between double and int data types? ♪ Int stands for integer. ♪ Double stands for all real numbers. ♫ How does the syntax for manipulating numeric data types and objects differ? ♪ Numeric number types is for adding and subtracting and objects are sent messages. ♫ Convert the following floating-point numbers to exponential notation: ♪ 23.5 = 2.35E1 ♪ 0.046 = 4.6E-3 ♫ Convert the following numbers from exponential notation to floating-point notation: ♪ 32.21E4 = 322,100 ♪ 55.6E-3 = 0.0556 ♫ Give two examples of string literals. ♪ “Enter degrees Fahrenheit.” ♪ “Enter the circumference of the circle.” ♫ Why is a variable called a variable? ♪ Because it stands in place of something else. ♫ Declare a floating-point variable called a payRate and simultaneously initialize it to $35.67. ♪ double payRate = 3.567E1;. ♫ Declare three integer variable (a, b ,c) in a single declaration and simultaneously initialize b to 4. ♪ int a, b = 4, c; . ♫ Give two types of data that cannot be stored in a variable of type int. ♪ Fractions and decimals. ♫ There are approximately 2.2 pounds in a kilogram. Name and declare a constant to represent this value. ♪ Final double KILOGRAM = 2.2;. ♫ Assume that the integer variable x is 5 and the integer variable y is 10. Give the values of the following expressions. ♪ x + y * 2 = 25 ♪ x – y + 2 = -3 ♪ (x + y) * 2 = 30 ♪ y%x=5 ♫ Find the syntax errors in the following expressions: ♪ a - * b + c = subtract and multiply cannot be next to each other. ♪ - ( a + b ) * c) = the last parentheses must have a counterpart. ♪ ( ) = there are no variables. ♫ Assume that x is 4.5 and y is 2. Write the values of the following exercises: ♪ x / y = 2.25 ♪ y / x = 0.44 ♪ x%y= 2 ♫ Assume that x and y are of type double and z is of type int. For each of the following assignment statements, state which are valid and which produce syntax errors: ♪ x = z syntax error ♪ x = y * z syntax error ♪ z = x + y ok ♫ Assume that x is of the type double and y is of the type int. Also assume that x is 4.5 and y is 2. Write the values of the following expressions: ♪ (int) x * y = 8 ♪ (int) (x * y) = 9 ♫ Assume that x is of type double and y is of type int. Write a statement that assigns the value contained in x to y after rounding this value to the nearest whole number. ♪ y = -5.2 n = (int) ( x – 0.5) ♫ Assume that x refers to the string “Wizard” and y refers to the string “Java”. Write the values of the following expressions: ♪ y + x = “JavaWizard” ♪ y + y.length( ) + x = Java4Wizard ♪ y + “\n” + x + “\n” = Java Wizard ♫ Declare a variable of type String called myInfo and initialize it to your name, address, and telephone number. Each item of information in this string should be followed by a newline character. ♪ String myInfo myInfo = “McKinley Craft \n” + “822 Jefferson Ave N \n” + “980- 3518 \n” ♫ Describe the purpose of each item of information that appears in a method’s signature. ♪ What type of value it returns. ♪ Its name. ♪ The number and type of the parameters it expects. ♫ State whether each of the following are valid or invalid user-defined symbols in Java: ♪ a. pricePerSquareInch = valid ♪ ♪ ♪ ♪ b. student2 = valid c.2GuysFromLexington = invalid d.PI = invalid e.allDone? = invalid ♫ Write names for the following items that follow good programming practice: ♪ a. A variable that represents the diameter of a circle. = Diameter ♪ b. A constant that represents the standard deduction for an income tax return. = STANDARDDEDUCTION ♪ c. A method that draws a rectangle. = DrawRectangle ♫ Describe the role of the items x, y, and, z in the statement import x.y.z;. ♪ X is the overall name of the package , y is the name of a subsection within the package, and z is the name of a particular class in the subsection. ♫ What happens when the computer executes the statement import x.y.*;? ♪ The star makes all classes in a package available. ♫ Assume that a program needs to use the class Format, which is included in the package BreezySwing. Show two ways to import this class with Java import statements. ♪ BreezySwing.Format; ♪ BreezySwing.*;