How to check for existing key in a hashtable in powershell?

You may need to check for the existence of an existing key or value for various purposes. Luckily Powershell hash table provides ready made methods which saves us a lot of pain of searching though the hash using a loop or some other construct.

To find if a key already exists use $hash.containsKey(key). Remember that if key is case insensitive if it happens to be a string. You can also use $hash.contains(key) mthod which is just a shortcut to containskey method.

Similarly to find a value already existing in the hash; use $hash.containsValue(value). Remember that values are case sensitive if they happens to a be a string.