How to edit my host file to enable three Cassandra nodes?

Question

This is my /etc/host

cat /etc/hosts
127.0.0.1   localhost
127.0.1.1   jholmes-System-Product-Name

My nodetool status

nodetool --host 127.0.0.1 status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address    Load       Tokens       Owns (effective)  Host ID                               Rack
UN  127.0.0.1  262.57 KiB  256          100.0%            d2d8baba-cee1-449a-b791-faec0d80b140  rack1

If I want to add three more nodes to Cassandra cluster(over single machine),is editing host file like this

127.0.0.2
127.0.0.3
127.0.0.4

sufficient? Will this be recognized by cassandra.yaml?