In the code, the $total2 of each product is placed in an array so that when the question is answered "no", we have "n" arrays. What loop can I do to add them all in a single variable and print it to the screen?

#!/bin/bash
clear
read -p "Do you want to continue shopping?: " response
while [ "$response" == 'yes' ]
   do
        read -p "What product are you going to buy?" product
        read -p "What is the price of this product?: " price
        read -p "How much of this product will you take?: " quantity
        lettotal2=expr $precio\*$cantidad
        echo "$product ($price €) X $quantity = $total2 €"
        array[i]=$total2
       ((i++))
        read -p "Do you want to continue shopping?: " response
        if [ "$answer" == 'no' ]
         then
           break
         fi
   donate     


here I want to add all the arrays created to show that sum on the screen.

echo "The total purchase price is $sum €."


#

It's my first question in the forum, so if I do something wrong I apologize in advance. I was trying to do an XSD exercise where the address element must be made up of any set of letters, then a blank space and finally a number between 1 and 200. For this I have to use the "pattern" constraint and talking about it with a colleague we thought of putting it like this:

   <xsd:element name="direccion">
     <xsd:simpleType>
      <xsd:restriction base="xsd:string">
       <xsd:pattern value="[a-z]*\b(200)|(1[0-9][0-9])|([1-9][0-9])|([1-9])"/>
      </xsd:restriction>
     </xsd:simpleType>
   </xsd:element>`

The problem is that it would not be quite right and also the validator gives me an error, I do not know if you would know how to change it so that it complies with the norm and does not give an error. Thank you very much.