add has_key? and has_value? methods on hashes

1 files changed, 4 insertions, 0 deletions

diff --git a/ruby.html.markdown b/ruby.html.markdown
index 800f0445..8c9d8fc5 100644
--- a/ruby.html.markdown
+++ b/ruby.html.markdown
@@ -191,6 +191,10 @@ new_hash = { defcon: 3, action: true }
 
 new_hash.keys #=> [:defcon, :action]
 
+# Check existence of keys and values in hash
+new_hash.has_key?(:defcon) #=> true
+new_hash.has_value?(3) #=> true
+
 # Tip: Both Arrays and Hashes are Enumerable
 # They share a lot of useful methods such as each, map, count, and more