SYNTAX

<Sequence> ->first.<attribute1>

Returns the value of <attribute1> of the first element in <Sequence>. Another operator, such as ->sortedBy, must be used to transform a <Collection> into a <Sequence> before ->first may be used. <Sequence> must be expressed as a unique alias.  See Advanced collection sorting syntax for more examples of usage.
<attribute1> may be of any data type.

USAGE RESTRICTIONS

The Operators row of the table in Summary Table of Vocabulary Usage Restriction applies. No special exceptions.

This sample Rulesheet uses ->first to identify the first element of the sequence created by applying ->sortedBy to collection1. Once identified, the value of the string1 attribute belonging to this first element is evaluated. If the value of string1 is Joe, then boolean1 attribute of Entity1 is assigned the value of true.

A sample Ruletest provides a collection of three elements, each with a decimal1 value. Input and Output panels are shown below.