CS 163/164, 🀨 Fall 2019 🀨

Lab 6 - Interfaces

Thursday, Sep. 12th or Friday, Sep. 13th

• To create a program according to specifications
• To create a program using an interface.
• To understand iterative development.

1. Create a new Java Project named Interfaces
2. Copy L6if.java and Test.java into the project, make sure they are in the "src" folder.
3. Create a class called Convert and have it implement L6if.
   • The TA will show you how to autogenerate method stubs from the interface and help you implement the first method toPounds.
4. Write the methods in the interface according to the pre and post conditions given below.
5. In Test.java the first test case is given to you. Read the comment and create additional test cases so your output matches the comment.
6. Show your code and output to the TA for credit.

1. This method has the following properties:
   • It is a public method, so "anyone" can call it.
   • It returns a double value to the calling function.
   • It takes one parameter of type double.
2. Preconditions:
   • The parameter is the temperature in Celsius.
3. Postconditions:
   • The return value is the temperature in Fahrenheit.

1. This method has the following properties:
   • It is a public method, so "anyone" can call it.
   • It returns an int value to the calling function.
   • It takes one parameter of type char.
2. Preconditions:
   • The parameter is the character to convert to ASCII.
3. Postconditions:
   • The return value is the ASCII value of the character.

1. This method has the following properties:
   • It is a public method, so "anyone" can call it.
   • It returns an String value to the calling function.
   • It takes one parameter of type String.
2. Preconditions:
   • The parameter is the string to put in web format.
3. Postconditions:
   • The return value is the web format of the string.

1. This method has the following properties:
   • It is a public method, so "anyone" can call it.
   • It returns an boolean value to the calling function.
   • It takes one parameter of type int.
2. Preconditions:
   • The parameter is the integer to check for "evenness".
3. Postconditions:
   • The return value is true if the parameter is even and false otherwise.

1. The comments in Test.java indicate we want your output to look like this:
   • 22.046226218487757
   • 68.0
   • 65
   • https://www.google.com
   • false
2. Follow the remaining comments in Test.java to write test cases for your methods.