Apex 嵌套if语句

if boolean_expression_1 {
   /* Executes when the boolean expression 1 is true */
   if boolean_expression_2 {
      /* Executes when the boolean expression 2 is true */
   }
}

String pinCode = '12345';
String customerType = '12345';
if (pinCode == '12345') {
    System.debug('Condition met and Pin Code is'+pinCode);

    if(customerType = 'Premium') {
        System.debug('This is a Premium customer living in pinCode 12345);
    }
    else if(customerType = 'Normal') {
        System.debug('This is a Normal customer living in pinCode 12345);
    }
}
else {
    //this can go on as per the requirement
    System.debug('Pincode not found');
}