FindNextItemNumber (Arraylist function): Difference between revisions

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{{Template:Arraylist:FindNextItemNumber subtitle}}
{{Template:Arraylist:FindNextItemNumber subtitle}}


This function searches "forward" in the <var>Arraylist</var> to find and return the item number of the next item that matches a specified criterion.  The criterion is supplied by the [[SelectionCriterion class|SelectionCriterion]] object that is a required <var>FindNextItemNumber</var> parameter. If no item satisfies the criterion, the method returns a zero.
<var>FindNextItemNumber</var> searches "forward" in the <var>Arraylist</var> to find and return the item number of the next item that matches a specified criterion.  The criterion is supplied by the [[SelectionCriterion class|SelectionCriterion]] object that is a required <var>FindNextItemNumber</var> parameter. If no item satisfies the criterion, the method returns a zero.


==Syntax==
==Syntax==
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<td>An <var>Arraylist</var> object. </td></tr>
<td>An <var>Arraylist</var> object. </td></tr>
<tr><th><i>selectionCriterion</i></th>
<tr><th><i>selectionCriterion</i></th>
<td>A <var class="term">[[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. For example, <code>GT(this, -11)</code> is the criterion <code>this</code> <code>></code> <code>-11</code>, where <code>this</code> is an identity function that simply returns the item's value. The first item tested by <var>FindNextItem</var> that satisfies this expression is the method's return value.<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> 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>
<td>A <var class="term">[[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 <code var ="term">this</code> is an identity function that simply returns the item's value. The first item tested by <var>FindNextItemNumber</var> that satisfies this expression is the method's return value.</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> 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>
<tr><th><b>Start</b></th><td>The <var class="term">number</var> of the item <b><i>after</i></b> which to begin the search. If the <var class="term">number</var> value of Start is 2, item 3 is the first item considered. The value of <var class="term">Start</var> may be 0 through the number of items in the collection. For a collection of three items, <var class="term">number</var> may be 0, 1, 2, or 3.<p>This is an optional argument, and it defaults to 0. If you specify a value, the parameter name <var class="term">Start</var> is required.</p></td></tr>
<tr><th><b>Start</b></th>
<td>The <var class="term">number</var> of the item <b><i>after</i></b> which to begin the search. If the <var class="term">number</var> value of Start is 2, item 3 is the first item considered. The value of <var class="term">Start</var> may be 0 through the number of items in the collection. For a collection of three items, <var class="term">number</var> may be 0, 1, 2, or 3.<p>This is an optional argument, and it defaults to 0. If you specify a value, the parameter name <var class="term">Start</var> is required.</p></td></tr>
</table>
</table>



Revision as of 04:01, 30 January 2011

Return number of matching item (Arraylist class)


FindNextItemNumber searches "forward" in the Arraylist to find and return the item number of the next item that matches a specified criterion. The criterion is supplied by the SelectionCriterion object that is a required FindNextItemNumber parameter. If no item satisfies the criterion, the method returns a zero.

Syntax

%number = al:FindNextItemNumber( selectionCriterion, [Start= number])

Syntax terms

%number A numeric variable to return the item number of the item that is located by the search.
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, GT(this, -11) is the criterion this > -11, where this is an identity function that simply returns the item's value. The first item tested by FindNextItemNumber that satisfies this expression is the method's return value.

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 declaration and that returns a numeric or string value. This is described further in Specifying a SelectionCriterion's parameters.

Start The number of the item after which to begin the search. If the number value of Start is 2, item 3 is the first item considered. The value of Start may be 0 through the number of items in the collection. For a collection of three items, number may be 0, 1, 2, or 3.

This is an optional argument, and it defaults to 0. If you specify a value, the parameter name Start is required.

Usage notes

  • If the value of start is greater than the number of items in the Arraylist, the request is cancelled. If the value of start is equal to the number of items, FindNextItemNumber returns a zero.
  • FindPreviousItemNumber is identical to FindNextItemNumber except that it searches backward in the Arraylist.
  • FindNextItemNumber is available in Sirius Mods version 7.6 and later.

Examples

  1. The following request contains two FindNextItemNumber calls, one with a simple selection criterion and one with a compound criterion:

    begin %al is arraylist of float %al = list(111, 29, 0, 93, 77, -345) %sel1 is object selectioncriterion for float %sel2 is object selectioncriterion for float %sel1 = GT(this, 100) %sel2 = AND(GE(this, 53), LT(this, 93)) printtext {~} is: {%al:findNextItemNumber(%sel1, start=1)} printtext {~} is: {%al:findNextItemNumber(%sel2)} end

    The result is:

    %al:findNextItemNumber(%sel1, start=1) is: 0 %al:findNextItemNumber(%sel2) is: 5

See also