---
- name: combination of variable string and array
  hosts: nodes
  vars:
     greeting: Hello User
     users:
        - Mohit
        - Rahul
        - Kartik
  tasks:
     - name: Calling variable
       debug:
          msg: "{{ greeting }} {{ users }}"

- name: combination of variable string and array
  hosts: nodes
  vars:
     greeting: Hello User
     users:
        - Mohit
        - Rahul
        - Kartik
  tasks:
     - name: Calling variable
       debug:
          msg: "{{ greeting }} {{ item }}"
       loop: "{{ users }}"
...