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   <TITLE>Convert an AnsiString to all lower case or upper case</TITLE>

   <META NAME="Author" CONTENT="Harold Howe">

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<H3>

Convert an <TT>AnsiString</TT> to all lower case or upper case

</H3>

<P>

The <TT>AnsiString</TT> class provides two member functions called <TT>UpperCase</TT> and

<TT>LowerCase</TT> that will accomplish what you need. <TT>UpperCase</TT> and

<TT>LowerCase</TT> are prototyped in the file <TT>DSTRING.H</TT>. The prototypes look like

this:

</P>

<pre>

AnsiString <b>__fastcall</b> LowerCase<b>(</b><b>)</b> <b>const</b><b>;</b>

AnsiString <b>__fastcall</b> UpperCase<b>(</b><b>)</b> <b>const</b><b>;</b>

</pre>

<P>

Notice that the functions are declared as <TT>const</TT> methods of <TT>AnsiString</TT>.

This allows you to call <TT>UpperCase</TT> or <TT>LowerCase</TT> on a constant

<TT>AnsiString</TT> object. The <TT>const</TT> declaration means that <TT>UpperCase</TT>

and <TT>LowerCase</TT> won't modify the current <TT>AnsiString</TT> object. This has an

important consequence: <TT>LowerCase</TT> and <TT>UpperCase</TT> return a new

<TT>AnsiString</TT> object that contains the converted string from the source object.

The original <TT>AnsiString</TT> object is not changed. Here is a code example that shows

how to use the functions:

</P>

<pre>

<font color="navy">// Example of how to correctly use UpperCase and LowerCase</font>

AnsiString str   <b>=</b> <font color="blue">"Hello Dr. Crane"</font><b>;</b>

AnsiString upper <b>=</b> str<b>.</b>UpperCase<b>(</b><b>)</b><b>;</b>    <font color="navy">// result= HELLO DR. CRANE</font>

AnsiString lower <b>=</b> str<b>.</b>LowerCase<b>(</b><b>)</b><b>;</b>    <font color="navy">// result= hello dr. crane</font>



<font color="navy">// Example of code that does nothing</font>

AnsiString str   <b>=</b> <font color="blue">"Hello Dr. Crane"</font><b>;</b>

str<b>.</b>UpperCase<b>(</b><b>)</b><b>;</b>  <font color="navy">// code has no effect, str is not modifed by UpperCase.</font>

</pre>

<P>

<B>Note:</B> The <TT>UpperCase</TT> and <TT>LowerCase</TT> methods of <TT>AnsiString</TT>

work by calling two global functions called <TT>AnsiUpperCase</TT> and <TT>AnsiLowerCase</TT>

in <TT>SYSUTILS.PAS</TT>. You can use the global functions if you prefer.

</P>

<P>

<B>Note:</B> I once needed to test a command line parameter as part of a programming

assignment. I used the code below to provide a case insensitive way of testing the

command line item.

</P>

<pre>

<b>if</b><b>(</b> <b>(</b>ParamCount<b>(</b><b>)</b> <b>>=</b> <font color="blue">1</font><b>)</b> <b>&&</b> <b>(</b>ParamStr<b>(</b><font color="blue">1</font><b>)</b><b>.</b>UpperCase<b>(</b><b>)</b> <b>==</b> <font color="blue">"-ISX"</font><b>)</b><b>)</b>

<b>{</b>

    <font color="navy">// do some cool stuff.</font>

<b>}</b>

</pre>



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