CountSubset (Arraylist function): Difference between revisions
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{{Template:Arraylist:CountSubset subtitle}} | {{Template:Arraylist:CountSubset subtitle}} | ||
==Syntax== | ==Syntax== | ||
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<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th>%count</th> | <tr><th>%count</th> | ||
<td> | <td>A numeric variable to contain the count of matching items.</td></tr> | ||
<tr><th>al</th> | <tr><th>al</th> | ||
<td>Arraylist object</td></tr> | <td>An <var>Arraylist</var> object.</td></tr> | ||
<tr><th>selectionCriterion</th> | <tr><th>selectionCriterion</th> | ||
<td><var>SelectionCriterion</var> object</td></tr> | <td>A <var>[[SelectionCriterion class|SelectionCriterion]]</var> object, which is a relational expression that is applied to an <var class="term">al</var> item value to determine whether the value satisfies the expression. The expression consists of a function, an operator, and a numeric or string value. | ||
<p> | |||
For example, <code>GT(this, -11)</code> is the criterion <code>this > -11</code>, where <var>this</var> is an identity function value that simply returns the item's value. The items that satisfy this expression populate the subset whose count <var>CountSubset</var> returns.</p> | |||
<p> | |||
The function in the criterion is a method value (a method or class member name literal, or a method variable) for a method that operates on items of the type specified on the <var class="term">al</var> <var>Arraylist</var> declaration and that returns a numeric or string value. This is described further in [[SelectionCriterion class#Specifying a SelectionCriterion's parameters|"Specifying a SelectionCriterion's parameters"]].</p></td></tr> | |||
</table> | </table> | ||
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==Examples== | ==Examples== | ||
The following request shows a <var>CountSubset</var> call with a simple selection criterion: | |||
<p class="code">begin | |||
%al is arraylist of float | |||
%al = list(111, 29, 0, 93, 77, -345) | |||
%sel is object selectioncriterion for float | |||
%sel = GT(this, 0) | |||
printText {~} = {%al:countSubset(%sel)} | |||
end | |||
</p> | |||
The result is: | |||
<p class="output">%al:countSubset(%sel) = 4 | |||
</p> | |||
==See also== | ==See also== | ||
{{Template:Arraylist:CountSubset footer}} | {{Template:Arraylist:CountSubset footer}} |
Latest revision as of 20:02, 17 July 2012
Number of items matching a criterion (Arraylist class)
[Introduced in Sirius Mods 7.8]
Syntax
%count = al:CountSubset( selectionCriterion)
Syntax terms
%count | A numeric variable to contain the count of matching items. |
---|---|
al | An Arraylist object. |
selectionCriterion | A SelectionCriterion object, which is a relational expression that is applied to an al item value to determine whether the value satisfies the expression. The expression consists of a function, an operator, and a numeric or string value.
For example, The function in the criterion is a method value (a method or class member name literal, or a method variable) for a method that operates on items of the type specified on the al Arraylist declaration and that returns a numeric or string value. This is described further in "Specifying a SelectionCriterion's parameters". |
Usage notes
- A CountSubset call with a particular selection criterion is equivalent to a count of the items in the subset returned by the SubsetNew method with that criterion.
Examples
The following request shows a CountSubset call with a simple selection criterion:
begin %al is arraylist of float %al = list(111, 29, 0, 93, 77, -345) %sel is object selectioncriterion for float %sel = GT(this, 0) printText {~} = {%al:countSubset(%sel)} end
The result is:
%al:countSubset(%sel) = 4