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| <span style="font-size:120%; color:black"><b><section begin=dpl_desc/>Find matching list item<section end=dpl_desc/></b></span>
| | #REDIRECT [[FindNextItem (GenericNamedArraylist function)]] |
| [[Category:UnicodeNamedArraylist methods|FindNextItem function]] | |
| <!--DPL?? Category:UnicodeNamedArraylist methods|FindNextItem function: Find matching list item-->
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| <p>
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| FindNextItem is a member of the [[UnicodeNamedArraylist class]]. | |
| </p>
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| This function searches “forward” in the UnicodeNamedArraylist to find and
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| return the next item that matches a specified criterion.
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| The criterion is supplied by the [[SelectionCriterion class|SelectionCriterion]] object
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| that is a required FindNextItem parameter.
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| If no item satisfies the criterion,
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| the request is cancelled and an ItemNotFound exception ([[??]] refid=itemnfe.)
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| is thrown.
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| ==Syntax==
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| %item = %unamrayl:FindNextItem(criterion -
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| [, Start=itemnum])
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| ===Syntax Terms===
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| <dl>
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| <dt><i>%item</i>
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| <dd>A variable of the type of the items in the UnicodeNamedArraylist to contain
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| the item that is located by the search.
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| <dt><i>%unamrayl</i>
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| <dd>A UnicodeNamedArraylist object.
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| <dt><i>criterion</i>
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| <dd>A SelectionCriterion object, which is a relational expression that is
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| applied to a ''%unamrayl'' item value to determine
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| whether the value satisfies the expression.
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| The expression consists of a function, an operator, and a User Language intrinsic type
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| (numeric, string, or Unicode) value.
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| For example, <tt>GT(this, 1)</tt> is the
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| criterion <tt>this</tt> <tt>></tt> <tt>1</tt>, where
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| <tt>this</tt> is an identity function that simply returns the item's value.
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| The first item tested by FindNextItem that satisfies this expression is
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| the method's return value.
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| The function in the criterion is
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| a method value (a method or class member name literal, or a method variable)
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| for a method
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| that operates on items of the type specified on the ''%unamrayl''
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| declaration and that returns an intrinsic value.
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| This is described further in "[[SelectionCriterion class#Specifying a SelectionCriterion's parameters|Specifying a SelectionCriterion's parameters]]".
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| <dt><b>Start=</b><i> itemnum</i>
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| <dd>The number of the item ''after'' which to begin the search.
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| If the ''itemnum'' value of Start is 2, item 3 is the first item considered.
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| The value of Start may be 0 through the number of items in
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| the UnicodeNamedArraylist.
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| For a UnicodeNamedArraylist of three items, ''itemnum'' may be 0, 1, 2,
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| or 3.
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| This is an optional argument, and it defaults to 0.
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| If you specify a value, the parameter name <tt>Start</tt> is required.
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| </dl>
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| ==Usage Notes==
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| <ul>
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| <li>If the value of Start is greater than the number of items in the
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| UnicodeNamedArraylist, the request is cancelled.
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| If the value of Start is equal to the number of items,
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| the request is cancelled, but an ItemNotFound exception is thrown.
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| <li>[[FindPreviousItem (UnicodeNamedArraylist function)|FindPreviousItem]]
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| is identical to FindNextItem except that it searches backward in the
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| UnicodeNamedArraylist.
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| </ul>
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| ==Examples==
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| The following request contains one FindNextItem call and one FindPreviousItem
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| call.
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| The FindPreviousItem call finds no matching item:
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| <pre style="xmp">
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| Begin
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| | |
| %k is unicodeNamedArraylist of longstring
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| %k = new
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| %k('§Jan':u) = 'Orion'
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| %k('§Apr':u) = 'Leo'
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| %k('§Mar':u) = 'Cancer'
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| %k('§Jun':u) = 'Ursa Minor'
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| %k('§Nov':u) = 'Andromeda'
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| %k('§Dec':u) = 'Aries'
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| %k('§Feb':u) = 'Canis Major'
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| %sel is object selectionCriterion for longstring
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| %sel2 is object selectionCriterion for longstring
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| %sel = OR(LT(this, 'C'), EQ(this, 'Taurus'))
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| %sel2 = EQ(this, 'Taurus')
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| Print %k:findNextitem(%sel)
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| Print %k:findPreviousitem(%sel2)
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| End
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| </pre>
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| The result is:
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| <pre style="xmp">
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| Aries
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| CANCELLING REQUEST: MSIR.0750: Class UNICODENAMEDARRAYLIST,
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| function FINDNEXTITEM: ITEMNOTFOUND exception: no items match
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| SelectionCriterion in line 31
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| </pre>
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