Computer Programming Concepts and Visual Basic David I. Schneider

458 Computer Programming Concepts and Visual Basic
THE IMMEDIATE WINDOW
You can set the focus to the Immediate window by clicking on it (if visible), by pressing
Ctrl+G, or by choosing “Immediate Window” from the View menu. Although the Immediate
window can be used during design time, it is primarily used in Break mode. When you type a
statement into the Immediate window and press the Enter key, the statement is executed at
once. A statement of the form
Print expression
displays the value of the expression on the next line of the Immediate window. In Figure D.1,
three statements have been executed. (When the program was interrupted, the variable numVar
had the value 10.) In addition to displaying values of expressions, the Immediate window also
is commonly used to change the value of a variable with an assignment statement before continuing
to run the program. Note 1: Any statement in the Immediate window can be executed
again by placing the cursor anywhere on the statement and pressing the Enter key. Note 2: In
earlier versions of Visual Basic the Immediate window was called the Debug window.
FIGURE D.1 Three Print Statements Executed in the Immediate Window
THE WATCH WINDOW
You can designate an expression as a watch expression or a break expression. Break expressions
are of two varieties: those that cause a break when they become true and those that cause
a break when they change value. At any time, the Watch window shows the current values of
all watch and break expressions. In the Watch window of Figure D.2, the type of each expression
is specified by an icon as shown in Table 1.
FIGURE D.2 The Watch Window
TABLE D.1
Watch Type Icons
Icon Type of expression
Watch expression
Break when expression is true
Break when expression has changed
The easiest way to add an expression to the Watch window is to right-click on a variable
in the code window and then click on “Add Watch” to call up an Add Watch dialog box. You