--- title: foo - test layout: api --- <div class='api-docs-breadcrumbs'><a href="test/index">test</a> / <a href="test/foo">foo</a></div> # foo <div class="overload-group" markdown="1"> <div class="signature"><code><span class="keyword">fun </span><span class="identifier">foo</span><span class="symbol">(</span><span class="symbol">)</span><span class="symbol">: </span><span class="identifier">Int</span></code></div> Groups elements of the original sequence by the key returned by the given <a href="#">keySelector</a> function applied to each element and returns a map where each group key is associated with a list of corresponding elements. ``` kotlin if (true) { println(property) } ``` </div> <div class="overload-group" markdown="1"> <div class="signature"><code><span class="keyword">fun </span><span class="identifier">foo</span><span class="symbol">(</span><span class="parameterName" id="$foo(kotlin.Int)/i">i</span><span class="symbol">:</span> <span class="identifier">Int</span><span class="symbol">)</span><span class="symbol">: </span><span class="identifier">Int</span></code></div> </div>