{"id":4353,"date":"2022-06-23T08:08:49","date_gmt":"2022-06-23T06:08:49","guid":{"rendered":"https:\/\/store.algosyntax.com\/?post_type=asx-lms-tutorial-cpt&p=4353"},"modified":"2026-03-09T05:09:53","modified_gmt":"2026-03-09T03:09:53","slug":"ue5-creating-predicates-for-tarray-tmap-and-tsets","status":"publish","type":"asx-lms-tutorial-cpt","link":"https:\/\/store.algosyntax.com\/tutorials\/unreal-engine\/ue5-creating-predicates-for-tarray-tmap-and-tsets\/","title":{"rendered":"UE5 Creating Predicates for TArray, TMap And TSets"},"content":{"rendered":"\t\t
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While trying to sort a TArray in unreal engine you may come across a requirement to define a\u00a0 PREDICATE_CLASS& Predicate. In this tutorial, we will explain this type and how to define your own. You will mostly encounter this while working in C++ with algorithms that deal with unreal engine containers like TArray and TMap.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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  1. What are Predicates In Unreal Engine<\/h2><\/li><\/ol>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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    A Predicate in Unreal Engine C++ API is a function that returns a bool that takes two objects of the same class and compares them.<\/p>

    \u00a0<\/p>

    How you compare the objects is up to you, you just need to return a bool when you are done. These type of functions will help unreal engine sort your TArray based on anything you would like.<\/p>

    \u00a0<\/p>

    For example you may wish to sort Actors by Mesh Size, their speed or any variable.\u00a0 If you have dealt with overriding comparison operators in C++ , then you’ll be very glad to know Predicates are very similar to that.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t

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      Common Functions That Require Predicates<\/h2>\n<\/li>\n<\/ol>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t
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      As mentioned in the intro, you may encounter Predicates when dealing with container algorithms like\u00a0<\/p>