How to check if a specific key is present in a hash or not?

I want to check whether the "user" key is present or not in the session hash. How can I do this?

Note that I don't want to check whether the key's value is nil or not. I just want to check whether the "user" *key* is present.

`Hash`'s `key?` method tells you whether a given key is present or not.

session.key?("user")

It is very late but preferably symbols should be used as key:

my_hash = {}
my_hash[:my_key] = 'value'

my_hash.has_key?("my_key")
=> false
my_hash.has_key?("my_key".to_sym)
=> true

my_hash2 = {}
my_hash2['my_key'] = 'value'

my_hash2.has_key?("my_key")
=> true
my_hash2.has_key?("my_key".to_sym)
=> false

But when creating hash if you pass string as key then it will search for the string in keys.

But when creating hash you pass symbol as key then has_key? will search the keys by using symbol.

---
If you are using Rails, you can use `Hash#with_indifferent_access` to avoid this; both `hash[:my_key]` and `hash["my_key"]` will point to the same record

You can always use `Hash#key?` to check if the key is present in a hash or not.

If not it will return you `false`

hash = { one: 1, two:2 }

hash.key?(:one)
#=> true

hash.key?(:four)
#=> false

While `Hash#has_key?` gets the job done, as Matz notes [here](

[To see links please register here]

), it has been deprecated in favour of `Hash#key?`.

hash.key?(some_key)

Another way is here

hash = {one: 1, two: 2}

hash.member?(:one)
#=> true

hash.member?(:five)
#=> false

In Rails 5, the **has_key?** method checks if key exists in hash. The syntax to use it is:

YourHash.has_key? :yourkey

Hash instance has a [`key?`][1] method:

{a: 1}.key?(:a)
=> true

Be sure to use the symbol key or a string key depending on what you have in your hash:

{'a' => 2}.key?(:a)
=> false

[1]:

[To see links please register here]

```
h = {}
if h.respond_to?(:key?) && h.key?('text') #with respond_to method check if it's hash
puts h['text']
end
```