Check if the variable/key exist

Question

I have a value customer with different condition :

• if customer = yes then score = 10
• if customer = no then score = 5
• if customer is null then

Answer 1

You did not check null for customer

     var customer = 
json.fields.customer != null && json.fields.customer.length > 0 ? json.fields.customer[0].value : null;