pascalabcnet/PABCNetHelp/LangGuide/FuncProgramming/Files/GroupJoin.html

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<H1>Ìåòîä GroupJoin</H1><h2>Îïèñàíèå ìåòîäîâ</h2><p>Ìåòîäû ïðèâåäåíû äëÿ ïîñëåäîâàòåëüíîñòè <code><b>sequence of</b> T</code>.</p><table>
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<code><b>function </b>GroupJoin&lt;TInner,Key,Res&gt;(inner: <b>sequence of</b> TInner; outerKeySelector: T-&gt;Key; innerKeySelector: TInner-&gt;TKey; resultSelector: (T,<b>sequence of</b> TInner)-&gt;Res): <b>sequence of</b> Res;</code>
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Îáúåäèíÿåò äâå ïîñëåäîâàòåëüíîñòè íà îñíîâå ðàâåíñòâà êëþ÷åé è ãðóïïèðóåò ðåçóëüòàòû. Çàòåì ôóíêöèÿ resultSelector ïðîåêòèðóåò êëþ÷ è ïîñëåäîâàòåëüíîñòü ñîîòâåòñòâóþùèõ åìó çíà÷åíèé íà ýëåìåíò ðåçóëüòèðóþùåé ïîñëåäîâàòåëüíîñòè.
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<code><b>function </b>GroupJoin&lt;TInner,Key,Res&gt;(inner: <b>sequence of</b> TInner; outerKeySelector: T-&gt;Key; innerKeySelector: TInner-&gt;TKey; resultSelector: (T,<b>sequence of</b> TInner)-&gt;Res; comparer: IEqualityComparer&lt;Key&gt;): <b>sequence of</b> Res;</code>
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Îáúåäèíÿåò äâå ïîñëåäîâàòåëüíîñòè íà îñíîâå ðàâåíñòâà êëþ÷åé è ãðóïïèðóåò ðåçóëüòàòû. Äëÿ ñðàâíåíèÿ êëþ÷åé èñïîëüçóåòñÿ óêàçàííûé êîìïàðàòîð. Çàòåì ôóíêöèÿ resultSelector ïðîåêòèðóåò êëþ÷ è ïîñëåäîâàòåëüíîñòü ñîîòâåòñòâóþùèõ åìó çíà÷åíèé íà ýëåìåíò ðåçóëüòèðóþùåé ïîñëåäîâàòåëüíîñòè.
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<h2>Ïðèìåð </h2><blockquote><code><strong>begin</strong><br>&nbsp; <strong>var</strong>
people := Arr((1,'Èâàíîâ'),(2,'Ïîïîâ'),(3,'Ñèäîðîâ'));<br>&nbsp; <strong>var</strong>
subjects := Arr((1,'Èñòîðèÿ'),(1,'Ìàòåìàòèêà'),(2,'Èñòîðèÿ')<br>&nbsp;&nbsp;&nbsp;
,(3,'Ìàòåìàòèêà'),(1,'Ðóññêèé'),(2,'Ôèçèêà'));<br><br>&nbsp;
people.GroupJoin(subjects,p-&gt;p[0],s-&gt;s[0],(p,ss)-&gt;(p[1],ss.Select(x-&gt;x[1]))).Println(NewLine);<br>
<strong>end</strong>.<br><br>Âûâîä:<br>(Èâàíîâ,[Èñòîðèÿ,Ìàòåìàòèêà,Ðóññêèé])<br>
(Ïîïîâ,[Èñòîðèÿ,Ôèçèêà])<br>(Ñèäîðîâ,[Ìàòåìàòèêà])</code></blockquote>
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