[user@server]# ./functions-and-variables.sh
Local Variable value before calling function1 = Australia
Local Variable value during calling function1 = NewZealand
Local Variable value after  calling function1 = Australia
Global Variable value before calling function1 = Earth
Global variable value during calling function1 = Mars
Global Variable value after  calling function1 = Mars

[user@server]# cat functions-and-variables.sh
#!/bin/bash
country=Australia
planet=Earth

function local_var_function {
              local country=NewZealand
              echo "Local Variable value during calling function1 = $country "
            }
    echo "Local Variable value before calling function1 = $country "
    local_var_function
    echo "Local Variable value after  calling function1 = $country "


function global_var_function {
              planet=Mars   #changing the global variable
              echo "Global variable value during calling function1 = $planet "
            }
    echo "Global Variable value before calling function1 = $planet "
    global_var_function
    echo "Global Variable value after  calling function1 = $planet "