{"id":2270,"date":"2023-12-14T17:56:28","date_gmt":"2023-12-14T16:56:28","guid":{"rendered":"https:\/\/oopm.org\/?page_id=2270"},"modified":"2024-12-15T12:07:35","modified_gmt":"2024-12-15T11:07:35","slug":"data-items","status":"publish","type":"page","link":"https:\/\/oopm.org\/?page_id=2270","title":{"rendered":"5. Data items"},"content":{"rendered":"
\"image_pdf\"<\/a>\"image_print\"<\/a><\/div>\n

In this chapter, we describe data-items that may represent references to objects, primitive values, string values, and composite values.<\/p>\n\n\n\n

As mentioned in previous chapters, objects may have attributes in the form of data-items that represent properties characterizing the corresponding phenomena. For the Account<\/code> example, we have seen examples of data-items such as owner<\/code>, balance<\/code>, and interestRate<\/code>:<\/p>\n\n\n\n

class<\/strong> Account(owner: ref<\/strong> Customer):\n   balance: var<\/strong> float\n   interestRate: var<\/strong> float\n   -\"-<\/code><\/pre>\n\n\n\n
There is a fundamental difference between the data-items owner<\/code> and balance<\/code>. While owner<\/code> is a reference<\/em> to the object representing the owner of the account (represented by an object of class Customer<\/code>), balance<\/code> represents a property that is given by a float<\/mark> <\/mark>value<\/em>. We return to this in section