diff --git a/core/java/android/util/SparseArray.java b/core/java/android/util/SparseArray.java
index 484894f980234..d3367c10bff5c 100644
--- a/core/java/android/util/SparseArray.java
+++ b/core/java/android/util/SparseArray.java
@@ -106,6 +106,9 @@ public class SparseArray<E> implements Cloneable {
     /**
      * Returns true if the key exists in the array. This is equivalent to
      * {@link #indexOfKey(int)} >= 0.
+     *
+     * @param key Potential key in the mapping
+     * @return true if the key is defined in the mapping
      */
     public boolean contains(int key) {
         return indexOfKey(key) >= 0;