FindPreviousItemNumber (GenericNamedArraylist function): Difference between revisions

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Item number of previous item that matches some selection criteria (FloatNamedArraylist, NamedArraylist, and UnicodeNamedArraylist classes)


FindPreviousItemNumber searches "backward" through the FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist to find and return the item number of the previous item that matches a specified criterion. The criterion is supplied by the SelectionCriterion object that is a required FindPreviousItemNumber parameter. If no item satisfies the criterion, the method returns a zero.

Syntax

%number = anyNal:FindPreviousItemNumber( selectionCriterion, [Start= number])

Syntax terms

%number A numeric variable to contain the item number of the item that is located by the search.
anyNal A FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist object.
selectionCriterion A SelectionCriterion object, which is a relational expression that is applied to a anyNal 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, LT(this, 11) is the criterion this < 11, where this is an identity function that simply returns the item's value. The item number of the first item tested by FindPreviousItemNumber 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 anyNal 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 before which to begin the search. If the value of Start is 4, item 3 is the first item considered. The value of Start may be 1 through one plus the number of items in the FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist. For a collection of three items, number may be 1, 2, 3, or 4.

This is an optional, but Name-Required, argument which defaults to one plus the number of items in the NamedArraylist. If you specify a value, the parameter name Start is required.

Usage notes

  • If the value of Start is not in the range of 2 through one plus the number of items in the FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist; the request is cancelled. If the value of Start is 1, no item can be found and the method returns a zero.
  • FindPreviousItemNumber is available in "Sirius Mods" Version 7.6 and later.

Examples

  1. The "FindNextItemNumber example" shows a FindPreviousItemNumber call.

See also

  • FindNextItemNumber is identical to FindPreviousItemNumber except that it searches forward in the FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist.