13 <p>Descriptors are self-describing strings that can be used to store binary

    13 <p>Descriptors are self-describing strings that can be used to

    14 data and text. Each descriptor object holds the length of the string as well

    14 store binary data and text. Each descriptor object holds the length

    15 as its type which identifies the underlying memory layout of the data it holds.

    15 of the string as well as its type which identifies the underlying

    16 For more information on different descriptor classes, see <xref href="GUID-11EEFB3D-0414-5BEB-9D78-56A4B9154008.dita">Using

    16 memory layout of the data it holds. For more information on different

    17 Descriptors</xref>.</p>

    17 descriptor classes, see <xref href="GUID-11EEFB3D-0414-5BEB-9D78-56A4B9154008.dita">Using Descriptors</xref>.</p>

    18 <p>There are modifiable and non-modifiable descriptors, the latter type

    18 <p>There are modifiable and non-modifiable descriptors, the latter

    19 is identified by a "C" suffix in the class name. The length of a non-modifiable

    19 type is identified by a "C" suffix in the class name. The length of

    20 descriptor is defined when compiling an application, and the length of a modifiable

    20 a non-modifiable descriptor is defined when compiling an application,

    21 descriptor can vary within the limits set by <codeph>iMaxLength</codeph>.

    21 and the length of a modifiable descriptor can vary within the limits

    22 Nonmodifiable descriptors are more secure, as their length is checked during

    22 set by <codeph>iMaxLength</codeph>. Nonmodifiable descriptors are

    23 compilation. The following figure shows the differences between these types.</p>

    23 more secure, as their length is checked during compilation. The following

    24 <fig id="GUID-A8F9937F-25A6-4E80-845F-35994B7E13E5"><title>Differences between modifiable, nonmodifiable, and pointer descriptors</title><image href="GUID-40619192-8C2F-4267-BFCA-F53E10BF5A31_d0e12529_href.png"/></fig>

    24 figure shows the differences between these types.</p>

    25 <p>When designing applications, avoid using fixed-length buffers as parameters

    25 <fig id="GUID-A8F9937F-25A6-4E80-845F-35994B7E13E5"><title>Differences between modifiable, nonmodifiable, and pointer

    26 and use base classes (preferably constant base type <codeph><xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Kernel_Architecture_2/e32cmn.hGlobals.html#%3a%3aTDesC" format="application/java-archive">TDesC</xref></codeph>)

    26 descriptors</title><image href="GUID-40619192-8C2F-4267-BFCA-F53E10BF5A31_d0e12633_href.png"/></fig>

    27 instead. Descriptor objects provide a flexible interface for manipulating

    27 <p>When designing applications, avoid using fixed-length buffers

    28 the contained string, including size and length checks. Take advantage of

    28 as parameters and use base classes (preferably constant base type <codeph><xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Kernel_Architecture_2/e32cmn.hGlobals.html#%3a%3aTDesC" format="application/java-archive">TDesC</xref></codeph>) instead. Descriptor objects provide

    29 these when possible.</p>

    29 a flexible interface for manipulating the contained string, including

    30 <p>For more information and examples, see the <xref href="GUID-0817AD1D-58CF-5108-ACBF-26DFD4BA395E.dita">Descriptors

    30 size and length checks. Take advantage of these when possible.</p>

    31 Overview</xref> topic.</p>

    31 <p>For more information and examples, see the <xref href="GUID-0817AD1D-58CF-5108-ACBF-26DFD4BA395E.dita">Descriptors Overview</xref> topic.</p>