Superx++ Lexicon: <arr> clause

<arr>

Purpose The <arr> clause is used to define an array within a class. It is not the same as the <arr> statement. There is a syntactical difference in the format of the two: the <arr> statement uses no curly braces around its initial element values whereas the <arr> clause does. Also, the purposes of the two are different. The <arr> clause defines a member array of a class, whereas the <arr> statement merely defines an array which is stand-alone.

Format <arr type="{datatype}" name="{name and size}">
   {comma-separated elements bounded by curly braces}
<arr>

{datatype} the datatype of the array and all its elements

{name and size} the name of the array followed by the number of elements in the array bounded by square brackets

{comma-separated elements bounded by curly braces} (optional) the initial values of the array elements should be separated by commas

What an Array defined in an Object looks like in Run-Time Memory

An array which is defined in a class will be created in an object when the object is instantiated. Let us assume that the object is called MyStudent and inherits from a class which contains the following array definition:
<arr type="int" name="score[5]">
   {100,50,75,90,95}
</arr>
The MyStudent object will look like this in run-time memory (assuming run-time memory was empty beforehand):
<xppRAM>
   <MyStudent arr_int_score.5.="{100,50,75,90,95}" />
</xppRAM>
where xppRAM is the memory object.

Renderings of an Array with Various Datatypes in Run-Time Memory

Datatype Rendering in Run-Time Memory

bool arr_bool_{array name}.{array size}.="{values}" />

date arr_date_{array name}.{array size}.="{values}" />

double arr_double_{array name}.{array size}.="{values}" />

float arr_float_{array name}.{array size}.="{values}" />

int arr_int_{array name}.{array size}.="{values}" />

long arr_long_{array name}.{array size}.="{values}" />

short arr_short_{array name}.{array size}.="{values}" />

string arr_string_{array name}.{array size}.="{values}" />

{array name} name of the array

{array size} number of elements in the array

{values} comma-separated list of the values of the array bounded by curly braces

Example #1 <class name="XStudent" inherit="">
   <construct />
   <scope type="public">
      <arr type="int" name="score[5]">
         {100,50,75,90,95}
      </arr>
   </scope>
</class>
Defines an array called score which has 5 elements: the value of the 1^st element is 100, the value of the 2^nd is 50 and so on.

Example #2 <class name="XStudent" inherit="">
   <construct />
   <scope type="public">
      <arr type="int" name="score[5]">
         {100,50,75,90,95}
      </arr>
   </scope>
</class>
<node name="MyStudent" class="XStudent" />
<xout>The 3rd array element has the value </xout>
<xout>
   <eval object="MyStudent" member="score[2]" />
</xout>
The same array, score[5], is defined in the class XStudent and the string The 3rd array element has the value 75 is sent to the output stream because 75 is returned as the value of score[2].

Example #3 <class name="XStudent" inherit="">
   <construct />
   <scope type="public">
      <arr type="int" name="score[5]">
         {100,50,75,90,95}
      </arr>
   </scope>
</class>
<node name="MyStudent" class="XStudent" />
<eval object="score[2]">99</eval>
<xout>The 3rd array element has the value </xout>
<xout>
   <eval object="MyStudent" member="score[2]" />
</xout>
The same array, score[5], is defined in the class XStudent. The MyStudent object is instantiated with the default values. Then the <eval> statement sets the score[2] is set to 99. The string The 3rd array element has the value 99 is sent to the output stream because 99 is returned as the value of score[2].

Purpose	The <arr> clause is used to define an array within a class. It is not the same as the <arr> statement. There is a syntactical difference in the format of the two: the <arr> statement uses no curly braces around its initial element values whereas the <arr> clause does. Also, the purposes of the two are different. The <arr> clause defines a member array of a class, whereas the <arr> statement merely defines an array which is stand-alone.
Format	<arr type="{datatype}" name="{name and size}"> {comma-separated elements bounded by curly braces} <arr>
	{datatype}	the datatype of the array and all its elements
	{name and size}	the name of the array followed by the number of elements in the array bounded by square brackets
	{comma-separated elements bounded by curly braces}	(optional) the initial values of the array elements should be separated by commas

What an Array defined in an Object looks like in Run-Time Memory
An array which is defined in a class will be created in an object when the object is instantiated. Let us assume that the object is called MyStudent and inherits from a class which contains the following array definition: <arr type="int" name="score[5]"> {100,50,75,90,95} </arr> The MyStudent object will look like this in run-time memory (assuming run-time memory was empty beforehand): <xppRAM> <MyStudent arr_int_score.5.="{100,50,75,90,95}" /> </xppRAM> where xppRAM is the memory object.

Renderings of an Array with Various Datatypes in Run-Time Memory
Datatype	Rendering in Run-Time Memory
bool	arr_bool_{array name}.{array size}.="{values}" />
date	arr_date_{array name}.{array size}.="{values}" />
double	arr_double_{array name}.{array size}.="{values}" />
float	arr_float_{array name}.{array size}.="{values}" />
int	arr_int_{array name}.{array size}.="{values}" />
long	arr_long_{array name}.{array size}.="{values}" />
short	arr_short_{array name}.{array size}.="{values}" />
string	arr_string_{array name}.{array size}.="{values}" />
{array name}	name of the array
{array size}	number of elements in the array
{values}	comma-separated list of the values of the array bounded by curly braces

Example #1	<class name="XStudent" inherit=""> <construct /> <scope type="public"> <arr type="int" name="score[5]"> {100,50,75,90,95} </arr> </scope> </class> Defines an array called score which has 5 elements: the value of the 1^st element is 100, the value of the 2^nd is 50 and so on.
Example #2	<class name="XStudent" inherit=""> <construct /> <scope type="public"> <arr type="int" name="score[5]"> {100,50,75,90,95} </arr> </scope> </class> <node name="MyStudent" class="XStudent" /> <xout>The 3rd array element has the value </xout> <xout> <eval object="MyStudent" member="score[2]" /> </xout> The same array, score[5], is defined in the class XStudent and the string The 3rd array element has the value 75 is sent to the output stream because 75 is returned as the value of score[2].
Example #3	<class name="XStudent" inherit=""> <construct /> <scope type="public"> <arr type="int" name="score[5]"> {100,50,75,90,95} </arr> </scope> </class> <node name="MyStudent" class="XStudent" /> <eval object="score[2]">99</eval> <xout>The 3rd array element has the value </xout> <xout> <eval object="MyStudent" member="score[2]" /> </xout> The same array, score[5], is defined in the class XStudent. The MyStudent object is instantiated with the default values. Then the <eval> statement sets the score[2] is set to 99. The string The 3rd array element has the value 99 is sent to the output stream because 99 is returned as the value of score[2].