VB Debugging Tools

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VB Debugging Tools

• Appendix D

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Why do we need debugging?

• Every program has errors, and the process of
  finding these errors is debugging
• Types of errors
• Syntax Errors
• Run Time Errors
• Logic Errors

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Debugging and Modes

• VB has three modes
• Design
• Run
• Break
• Syntax Errors show up during design mode
• Run Time Errors show up during run mode and
  invoke break mode
• When do Logic errors show up?

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Syntax Errors

• How do they show up?????

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Run Time Errors

• How about them???

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Logic Errors

• Well???
• Im waiting
• Maybe a good start is to find out what they
  really are

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Visual Basic 6.0 Tools

• Immediate Window You can type a statement in
  the immediate window, press enter, and the stmt
  you typed is executed.
• The Immediate window is used to find what the
  value of variables are when the programmer
  selects the break mode

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Visual Basic 6.0 Tools p-2

• Watch Window is used to monitor (watch) an
  expression or a break expression.
• At any time, the watch window shows the current
  values of all watch and break expressions
• We add expressions to the Watch Window by
  right-click on a variable in the code window and
  add to watch. We can also edit and delete
  expressions.

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Visual Basic 6.0 Tools p-3

• Locals Window displays the names, values, and
  types of all variables in the current procedure.
• Values of variables can be altered at any time in
  this window
• Properties of objects can be modified through
  this window as well

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STEP

• Step Through F8 line by line
• Step Over Shift / F8 skip a procedure
• Step Out Ctrl / Shift / F8 execute remainder
• These are handled manually with these key
  strokes, I use them all the time

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BreakPoints

• Setting F9 Program will execute up to this
  point
• Removing F9
• Clear All - Ctrl / Shift / F9
• Set next Stmt Ctrl / F9
• Continue or Advance F5
• Run to cursor Ctrl / F8