Unit #2-02

Learning Outcome

At the end of this lesson, you will be able to:

• understand and use properties in a class

Review

• basics of OOP

Lesson

• read "Using OOP", Chapter 8, Computer Based Problem Solving

  • read "Property Members" & "Read only Property Members"

• fields need to be declared as "private" so that no one can change them!

• Typescript Getters and Setters
  
  public get age(): number {

    return this._age

}

public set age(theAge: number): void {

    if (theAge <= 0 || theAge >= 200) {

        throw new Error('The age is invalid')

    }

    this._age = theAge

• Java Getters and Setters

Activity

• go over the Bicycle Class example:

  • Bicycle Example - TypeScript

  • Bicycle Example - Java

Daily Assignment

• continue to re-create the MrCoxallStack from last time:

  • you already have pushItem(stringItem), now add popItem() -> stringItem

    • remove the top item and return it

  • add "getters" and "setters" for each of the fields

    • it turns out for MrCoxallStack, you currently only have 1 field and it is a list

      • you should not be able to change it, so remove your showStack() method and make it a getter

Extra

• do the above in a second language