Class 27: Vectors

Held Wednesday, March 10

Summary

• Vectors
• Vectors vs.
  • lists
  • arrays
  • sequences
• Lab: X2: Vectors

Contents

Notes

• I may not be here today (predicting sick children). In that case, Mr. Flynt will teach the class.
• I'll distribute the next exam on Friday. It will be due right before break.

Vectors

• You may wonder why Java provides some standard data structures, like arrays, but not others.
  • For example, Java does not provide a list data type as one of it's libraries.
• Some of the reasons have to do with design. As you can tell, there seem to be a lot of design possibilities in the choice of methods to include in a list.
  • And yes, it does stir controversies.
• Java does include a standard utility class, java.util.Vector, that is quite similar to a form of ordered list. However, vectors also have some similarities to arrays
• Like ordered lists,
  • vectors let you put things in various places;
  • vectors grow dynamically;
  • vectors maintain ordering after deletion.
• Like arrays,
  • vectors support indexed access to elements;
  • vectors let you change elements.
• In addition,
  • vectors add some support for table-like operations.

Lab

• Do X2.2 and X2.3.

History

• Created Monday, January 11, 1999.
• Added short summary on Friday, January 22, 1999.
• Filled in some details on Tuesday, March 9, 1999.