From c295de09ea738d71b16bd18b4ff169828297d584 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miroslav=20C=CC=8Cech?= <miroslav.cech@gooddata.com>
Date: Tue, 19 Oct 2021 16:24:53 +0200
Subject: [PATCH] Introduce obtaining list of object's keys.

---
 problems/objects/README.md    | 8 +++++++-
 problems/objects/problem.json | 5 +++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/problems/objects/README.md b/problems/objects/README.md
index 9d8cab0..3655010 100644
--- a/problems/objects/README.md
+++ b/problems/objects/README.md
@@ -1,4 +1,4 @@
-Constructing objects
+Working with objects
 ========================================
 
 `jq` can also be used to transform data. For instance, to construct a
@@ -19,3 +19,9 @@ it will be copied into the output object:
     $ echo '{"foo": { "bar": "a value" }}' \
       | jq '{ foo, why: "demonstration copy" }'
 
+`jq` can also transform object into a list of `key` and `value` pairs
+with `to_entries` function:
+
+    $ echo '{"banana": "yellow", "blueberry": "blue"}' \
+      | jq to_entries
+
diff --git a/problems/objects/problem.json b/problems/objects/problem.json
index 075bbe0..09b1923 100644
--- a/problems/objects/problem.json
+++ b/problems/objects/problem.json
@@ -18,6 +18,11 @@
     "prompt": "Construct a new object with the 'name' field renamed to 'title'",
     "dataset": "product",
     "solution": "{ price, title: .name}"
+  },
+  {
+    "prompt": "Construct a list of all properties (keys) of a product",
+    "dataset": "product",
+    "solution": "to_entries | [.[].key]"
   }
 ]