How to return the value to the function calling using return key

The below code snippet shows how to return the value to the function calling and how to override the delcared variable value.

funReturn1()
{
  x=10;
  echo "$x"
}
rvalue=`funReturn1`
echo -e "function funReturn return rvalue = $rvalue\n"
y=10;
funReturn()
{
  y=20;
  return;
}
funReturn
echo -e "function funReturn return y = $y\n"

OUTPUT :

-bash-3.2$ sh func_return
function funReturn return rvalue = 10
function funReturn return y = 20
-bash-3.2$
Explanation :

function funReturn1 is just return the value to the function calling and assign the return value into rvalue variable here only one echo statement is used dont use more than one echo statement.

y=10; # declared the value in global
funReturn()
{
  y=20; # here the value y=10 is reassigned to y=20 after the function call the value should be updated to y=20
  return;
}
funReturn