Section 1.28 Unit 1B Projects

Subsection 1.28.1 Method Headers and Method Calls Review

• The method header defines the method.
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• The method call uses (invokes) the method.
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• The arguments in a method call must match the parameters in the method header.
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• If a method returns a value, you can store it in a variable, use it in an expression, or print it.
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Subsection 1.28.2 Unit 1B Project 1 - My Shape

1. In the main method, declare appropriate variables for length, width, and the rectangle’s area (do not initialize them). These should allow for decimal values. Create a scanner object, and prompt the user to enter values for length and width, storing those values into the appropriate variables.
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2. Complete the body of the perimeter method so that it calculates and prints the perimeter of the rectangle (make sure to add words to the print statement so the output shows that the value represents the perimeter).
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3. Back in main, call the perimeter method, sending in the appropriate variables.
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4. Complete the body of the area method so that it calculates and returns the value of the area of the rectangle.
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5. Back in main, call the area method, sending in the appropriate variables, and store the result of the call into your area variable. Still in main, print the area of the rectangle (make sure to add words to the print statement so the output shows that the value represents the area).
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6. Test your program to make sure both area and perimeter are calculating and printing correctly.
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Subsection 1.28.3 Static Methods Review

• Static methods belong to the class.
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• You can call a static method without creating an object.
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• If the method is in another class, use ClassName.methodName(...)
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• Provide the required arguments in the correct order and type when calling the method.
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public class Geometry
{
    public static double findArea(double length, double width)
    {
        return length * width;
    }
}

Subsection 1.28.4 Unit 1B Project 2 - Round Things

1. calcAreaCircle() - receives the radius of a circle, and returns the area
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2. calcCircumCircle() - receives the radius of a circle and returns the circumference
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3. calcAreaSphere() - receives the radius of a Sphere and returns the area
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4. calcVolumeSphere() - receives the radius of a Sphere and returns the volume - watch out for integer division!
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1. radius - input variable, a double value (to be gotten from the user using a Scanner)
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2. area - a double value returned from the calcAreaCircle method
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3. circumference - a double value returned from the calcCircumCircle method
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4. surfaceArea - a double value returned from the calcAreaSphere method
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5. volume - a double value returned from the calcVolumeSphere method
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The area of a circle with a radius of # is #.
The volume of a sphere with a radius of # is #. 
(# will be replaced by the appropriate value)

Subsection 1.28.5 String Methods Review

String word = "computer";
int index = word.indexOf("p"); // index is 3

String word = "computer";
String part = word.substring(3); // "puter"

String word = "computer";
String part = word.substring(3, 6); // "put"

• String indexing begins at 0.
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• indexOf() returns the first matching index or -1 if not found.
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• substring(beginIndex) goes to the end of the string.
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• substring(beginIndex, endIndex) does not include the character at endIndex.
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Subsection 1.28.6 Unit 1B Project 3 - String Program

Original: one*two*three*four
Reverse: four three two one