# 
#  Overview
We can check if a particular hash contains a particular key by using the method **`has_key?(key)`**. It returns `true` or `false` depending on whether the key exists in the hash or not.
# 
#  Syntax
```ruby
hash.has_key?(key)
```
# 
## Parameters
**`hash`**: This is the hash we want to access the keys of.

**`key`**: This is the key we want to check to see if hash `hash` contains it.
##
## Return value
`true` is returned if the hash, `hash`, contains the key, `key`. Otherwise, a `false` is returned.
##
## Code example


# create hashes
h1 = {one: 1, two: 2, three: 3}
h2 = {name: "okwudili", stack: "ruby"}
h3 = {"foo": 0, "bar": 1}
h4 = {M:"Mango", A: "Apple", B: "Banana"}

# check for some keys
puts h1.has_key?(:one)
puts h2.has_key?(:name)
puts h3.has_key?(:foobar)
puts h4.has_key?(:C)

## Explanation
* **Lines 2-5**: We create the hashes `h1`, `h2`, `h3`, and`h4`.
* **Lines 8-11**: We check some keys to see if they were contained in some hashes. We then print the results to the console.

How to check if a hash contains a particular key in Ruby

Overview

Syntax

Parameters

Return value

Code example

Explanation