basic_stmt.htm

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<i>Statements</i>
<blockquote>
One or more <font color="black"><i>statements</i></font> that are repeated while or until <font color="black"><i>condition</i></font> is True.
</blockquote>
</blockquote>
<H4>
Example 1
</H4>
<pre>
<font color="blue"><b>Dim</b></font> x <font color="blue"><b>As</b></font> <font color="blue"><b>Integer</b></font> = 10
<font color="blue"><b>Do</b></font> 
  <font color="blue"><b>print</b></font> x
  <font color="blue"><b>If</b></font> x = 5 <font color="blue"><b>Then</b></font>
    <font color="blue"><b>Exit</b></font> <font color="blue"><b>Do</b></font>
  <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font> 
  x = x - 1 
<font color="blue"><b>Loop</b></font> <font color="blue"><b>Until</b></font> x = 0
</pre>
<H4>
Example 2
</H4>
<pre>
<font color="blue"><b>Dim</b></font> x <font color="blue"><b>As</b></font> <font color="blue"><b>Integer</b></font> = 10 
<font color="blue"><b>Do</b></font> <font color="blue"><b>While</b></font> x > 0
  <font color="blue"><b>print</b></font> x
  x = x - 1 
  <font color="blue"><b>If</b></font> x = 5 <font color="blue"><b>Then</b></font>
    <font color="blue"><b>Exit</b></font> <font color="blue"><b>Do</b></font>
  <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font> 
<font color="blue"><b>Loop</b></font>
</pre>
<H4>
See Also
</H4>
<blockquote>
<ul>
<li><a href="#Exit Statements">Exit Statements</a></li>
<li><a href="#For-Next Statements">For-Next Statements</a></li>
<li><a href="#While Statements">While Statements</a></li>
<//ul>
</blockquote>
</blockquote>
<a name="Enum Statements"><h3>Enum Statements</h3></a>
<!-------------------------------------------------------------------->
<blockquote>
Creates enumeration type
<H4>
Grammar
</H4>
<blockquote>
<pre>
EnumStmt -> <font color="blue"><b>Enum</b></font> TypeName
              Ident { = Number }
              ..............
            <font color="blue"><b>End</b></font> <font color="blue"><b>Enum</b></font>
</pre>
</blockquote>
<H4>
Example
</H4>
<pre>
<font color="blue"><b>Enum</b></font> E
  A
  B = 10
  C
<font color="blue"><b>End</b></font> <font color="blue"><b>Enum</b></font>
<font color="blue"><b>Dim</b></font> X <font color="blue"><b>As</b></font> E
<font color="blue"><b>print</b></font> X.A
<font color="blue"><b>print</b></font> X.B
<font color="blue"><b>print</b></font> X.C
</pre>
</blockquote>
<a name="Exit Statements"><h3>Exit Statements</h3></a>
<!-------------------------------------------------------------------->
<blockquote>
Exits a block of Do...Loop, For...Next, Function, or Sub code.
<H4>
Grammar
</H4>
<blockquote>
<pre>
ExitStmt -> <font color="blue"><b>Exit</b></font> <font color="blue"><b>Do</b></font> |
            <font color="blue"><b>Exit</b></font> <font color="blue"><b>For</b></font> |
            <font color="blue"><b>Exit</b></font> <font color="blue"><b>Function</b></font> |
            <font color="blue"><b>Exit</b></font> <font color="blue"><b>Property</b></font> |
            <font color="blue"><b>Exit</b></font> <font color="blue"><b>Sub</b></font> |
</pre>
</blockquote>
<H4>
Arguments
</H4>
<blockquote>
<i>Exit Do</i>
<blockquote>
Provides a way to exit a Do...Loop statement.
</blockquote>
</blockquote>
<blockquote>
<i>Exit For</i>
<blockquote>
Provides a way to exit a For loop.
</blockquote>
</blockquote>
<blockquote>
<i>Exit Function</i>
<blockquote>
Immediately exits the Function procedure in which it appears.
</blockquote>
</blockquote>
<blockquote>
<i>Exit Property</i>
<blockquote>
Immediately exits the Property procedure in which it appears.
</blockquote>
</blockquote>
<blockquote>
<i>Exit Sub</i>
<blockquote>
Immediately exits the Sub procedure in which it appears.
</blockquote>
</blockquote>
<H4>
Example 1
</H4>
<pre>
x = 10 
<font color="blue"><b>Do</b></font> <font color="blue"><b>While</b></font> x > 0
  <font color="blue"><b>print</b></font> x
  x = x - 1 
  <font color="blue"><b>If</b></font> x = 5 <font color="blue"><b>Then</b></font>
    <font color="blue"><b>Exit</b></font> <font color="blue"><b>Do</b></font>
  <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font> 
<font color="blue"><b>Loop</b></font>
</pre>
<H4>
Example 2
</H4>
<pre>
<font color="blue"><b>For</b></font> i = 5 <font color="blue"><b>to</b></font> 1 <font color="blue"><b>Step</b></font> -1
  <font color="blue"><b>If</b></font> i = 2 <font color="blue"><b>Then</b></font>
    <font color="blue"><b>Exit</b></font> <font color="blue"><b>For</b></font>
  <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font> 
  <font color="blue"><b>print</b></font> i
<font color="blue"><b>Next</b></font>
</pre>
<H4>
See Also
</H4>
<blockquote>
<ul>
<li><a href="#Do-loop statements">Do-loop statements</a></li>
<li><a href="#For-Next Statements">For-Next Statements</a></li>
<li><a href="#Function Statements">Function Statements</a></li>
<li><a href="#Sub Statements">Sub Statements</a></li>
<li><a href="#Property Statements">Property Statements</a></li>
<//ul>
</blockquote>
</blockquote>
<a name="For-Next Statements"><h3>For-Next Statements</h3></a>
<!-------------------------------------------------------------------->
<blockquote>
Repeats a group of statements a specified number of times.
<H4>
Grammar
</H4>
<blockquote>
<pre>
<font color="blue"><b>For</b></font>-NextStmt -> <font color="blue"><b>For</b></font> Counter = InitialValue <font color="blue"><b>To</b></font> FinalValue [<font color="blue"><b>Step</b></font> StepValue]
  [Statements]
  [<font color="blue"><b>Exit</b></font> <font color="blue"><b>For</b></font>]
  [Statements]
<font color="blue"><b>Next</b></font> [ NextExpressionList ] 

NextExpressionList -> Counter/<font color="Red">','</font>...
</pre>
</blockquote>
<H4>
Arguments
</H4>
<blockquote>
<i>Counter</i>
<blockquote>
Numeric variable used as a loop <font color="black"><i>counter</i></font>. The variable can't be an array element or an element of 
a user-defined type.
</blockquote>
</blockquote>
<blockquote>
<i>InitialValue</i>
<blockquote>
Initial value of <font color="black"><i>Counter</i></font>.
</blockquote>
</blockquote>
<blockquote>
<i>FinalValue</i>
<blockquote>
Final value of <font color="black"><i>Counter</i></font>.
</blockquote>
</blockquote>
<blockquote>
<i>StepValue</i>
<blockquote>
Amount <font color="black"><i>Counter</i></font> is changed each time through the loop. If not specified, <font color="black"><i>StepValue</i></font> defaults to one.
</blockquote>
</blockquote>
<blockquote>
<i>Statements</i>
<blockquote>
One or more <font color="black"><i>statements</i></font> between For and Next that are executed the specified number of times.
</blockquote>
</blockquote>
<H4>
Example 1
</H4>
<pre>
<font color="blue"><b>For</b></font> i = 5 <font color="blue"><b>to</b></font> 1 <font color="blue"><b>Step</b></font> -1
  <font color="blue"><b>If</b></font> i = 2 <font color="blue"><b>Then</b></font>
    <font color="blue"><b>Exit</b></font> <font color="blue"><b>For</b></font>
  <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font> 
  <font color="blue"><b>print</b></font> i
<font color="blue"><b>Next</b></font>
</pre>
A Next statement with one or more variables will, from left to right, close the For loops that match each variable. If a variable closes a For loop that is not the most nested loop at that point, a compile-time error results.
<H4>
Example 2
</H4>
<pre>
<font color="blue"><b>Dim</b></font> I, J
<font color="blue"><b>For</b></font> I = 1 <font color="blue"><b>To</b></font> 2
  <font color="blue"><b>For</b></font> J = 1 <font color="blue"><b>to</b></font> 3
    <font color="blue"><b>print</b></font> I, <font color="Red">" "</font>, J
<font color="blue"><b>Next</b></font> J, I
</pre>
<H4>
See Also
</H4>
<blockquote>
<ul>
<li><a href="#Do-loop statements">Do-loop statements</a></li>
<li><a href="#Exit Statements">Exit Statements</a></li>
<li><a href="#While Statements">While Statements</a></li>
<//ul>
</blockquote>
</blockquote>
<a name="Function Statements"><h3>Function Statements</h3></a>
<!-------------------------------------------------------------------->
<blockquote>
Declares the name, arguments, and code that form the body of a function.
<H4>
Grammar
</H4>
<blockquote>
<pre>
FunctionStmt -> [<font color="blue"><b>Shared</b></font>] <font color="blue"><b>Function</b></font> Ident [<font color="Red">'('</font> FormalParam/<font color="Red">','</font>... <font color="Red">')'</font>] <font color="Red">';'</font>
                  Statements
                <font color="blue"><b>End</b></font> <font color="blue"><b>Function</b></font>
FormalParam -> [<font color="blue"><b>ByRef</b></font>] Parameter
</pre>
</blockquote>
<H4>
Arguments
</H4>
<blockquote>
<i>Ident</i>
<blockquote>
Name of function.
</blockquote>
</blockquote>
<blockquote>
<i>Parameter</i>
<blockquote>
Represents formal <font color="black"><i>parameter</i></font> of function. The ByRef keyword indicates that the 
argument is passed by reference.
</blockquote>
</blockquote>
<blockquote>
<i>Statements</i>
<blockquote>
One or more <font color="black"><i>statements</i></font> separated by colons.
</blockquote>
</blockquote>
<blockquote>
<i>Shared</i>
<blockquote>
Optional. The <font color="black"><i>shared</i></font> keyword specifies a static (<font color="black"><i>shared</i></font>) method of a class. Can be used only inside of a class body.
</blockquote>
</blockquote>
<H4>
Example 1
</H4>
<pre>
<font color="blue"><b>Function</b></font> Fact(N)
  <font color="blue"><b>If</b></font> N = 1 <font color="blue"><b>Then</b></font> 
    <font color="blue"><b>return</b></font> 1
  <font color="blue"><b>Else</b></font>
    <font color="blue"><b>return</b></font> N * Fact(N - 1)
  <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font>
<font color="blue"><b>End</b></font> <font color="blue"><b>Function</b></font>
</pre>
You can use the function statement inside of a class body. In such case the statement declares a method of the class.
<H4>
Example 2
</H4>
<pre>
<font color="blue"><b>Class</b></font> <font color="blue"><b>MyClass</b></font>
  <font color="blue"><b>Dim</b></font> Z = <font color="Red">"abc"</font>
  <font color="blue"><b>Sub</b></font> <font color="blue"><b>New</b></font>()
  <font color="blue"><b>End</b></font> <font color="blue"><b>Sub</b></font>
  <font color="blue"><b>Function</b></font> DoubleZ()
    <font color="blue"><b>return</b></font> Z + Z
  <font color="blue"><b>End</b></font> <font color="blue"><b>Function</b></font>
  <font color="blue"><b>Shared</b></font> <font color="blue"><b>Function</b></font> Hello()
    <font color="blue"><b>return</b></font> <font color="Red">"Hello "</font> + ClassName
  <font color="blue"><b>End</b></font> <font color="blue"><b>Function</b></font>
<font color="blue"><b>End</b></font> <font color="blue"><b>Class</b></font>
</pre>
<H4>
See Also
</H4>
<blockquote>
<ul>
<li><a href="#Class Statements">Class Statements</a></li>
<li><a href="#Sub Statements">Sub Statements</a></li>
<//ul>
</blockquote>
</blockquote>
<a name="If Statements"><h3>If Statements</h3></a>
<!-------------------------------------------------------------------->
<blockquote>
Conditionally executes a group of statements, depending on the value of an expression.
<H4>
Grammar
</H4>
<blockquote>
<pre>
IFStmt -> <font color="blue"><b>If</b></font> Condition <font color="blue"><b>Then</b></font> 
             Statements 
          [<font color="blue"><b>ElseIf</b></font> Condition-n <font color="blue"><b>Then</b></font>
             ElseifStatements] 
          /...
          [<font color="blue"><b>Else</b></font> 
             ElseStatements] 
          <font color="blue"><b>End</b></font> <font color="blue"><b>If</b></font>
</pre>
</blockquote>
<H4>
Arguments
</H4>
<blockquote>
<i>Condition</i>
<blockquote>
A Boolean expression. If <font color="black"><i>condition</i></font> is null or undefined, <font color="black"><i>condition</i></font> is treated as false.
</blockquote>
</blockquote>
<blockquote>
<i>Condition-n</i>
<blockquote>
The same as <font color="black"><i>Condition</i></font>.
</blockquote>
</blockquote>
<blockquote>
<i>Statements</i>