{"id":415,"date":"2023-05-14T13:30:01","date_gmt":"2023-05-14T11:30:01","guid":{"rendered":"https:\/\/oopm.org\/?page_id=415"},"modified":"2025-01-12T13:26:44","modified_gmt":"2025-01-12T12:26:44","slug":"2-5-method-with-parameter","status":"publish","type":"page","link":"https:\/\/oopm.org\/?page_id=415","title":{"rendered":"2.6 Method with parameter"},"content":{"rendered":"
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Next, we add a method for depositing an amount to the account, and since the amount to be deposited in most cases differ from time to time it is possible to define a method with a parameter defining the amount to be deposited.<\/p>\n\n\n\n

In the next example, we add a method deposit<\/code>, with a parameter amount<\/code>:<\/p>\n\n\n\n

account_1010: obj<\/strong>\n   owner: val<\/strong> \"John Smith\"\n   balance: var<\/strong> float\n   interestRate: var<\/strong> float\n   addInterest:\n      balance := balance + (balance * interestRate) \/ 100\n   deposit(amount: var<\/strong> float):\n      balance := balance + amount<\/code><\/pre>\n\n\n\n
The variable amount<\/code> is a parameter<\/em> of deposit<\/code>. A value for amount<\/code> must be supplied when deposit<\/code> is invoked as shown here:<\/p>\n\n\n\n
account_1010.deposit(100)<\/code><\/pre>\n\n\n\n
The value supplied (here 100) is called the actual paramete<\/em>r of deposit<\/code> in contrast to amount<\/code>, which is called the formal parameter<\/em>. The term parameter<\/em> is often used to mean the formal parameter whereas the term argument<\/em> means the actual parameter.<\/p>\n\n\n\n
The above statement is an example of a method invocation<\/em>. It implies that an instance of deposit<\/code> is generated, and this implies that a computation as described by deposit<\/code> is carried out <\/mark>by execution of the statement balance := balance + amount<\/code>.<\/p>\n\n\n\n
In this computation, the value 100 is supplied for amount<\/code>. This means that amount<\/code> holds the value 100 when the assignment statement of deposit<\/code> is executed. The body of deposit<\/code> adds amount<\/code> to the current value of balance<\/code>. If balance<\/code> holds the value 350.56 before invocation of the method, it holds the value 450.56 after the execution of the invocation.<\/p>\n\n\n\n
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Method invocation<\/figcaption><\/figure>\n\n\n\n
An instance of deposit<\/code> is called a method object<\/em> and is in many ways similar to an object like account_1010<\/code> – we return to this later.<\/p>\n\n\n\n
In general, a method may have local data-items like owner<\/code>, balance<\/code> and interestRate<\/code> of account_1010<\/code>. The parameter amount<\/code> is also an attribute (data-item) of the method object.<\/p>\n
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Next, we add a method for depositing an amount to the account, and since the amount to be deposited in most cases differ from time to time it is possible to define a method with a parameter defining the amount to be deposited. In the next example, we add a method deposit, with a parameter amount: The […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":175,"menu_order":6,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-415","page","type-page","status-publish","hentry"],"mb":[],"mfb_rest_fields":["title","gutenberg_elementor_mode"],"_links":{"self":[{"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/415","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/oopm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=415"}],"version-history":[{"count":34,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/415\/revisions"}],"predecessor-version":[{"id":10989,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/415\/revisions\/10989"}],"up":[{"embeddable":true,"href":"https:\/\/oopm.org\/index.php?rest_route=\/wp\/v2\/pages\/175"}],"wp:attachment":[{"href":"https:\/\/oopm.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=415"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}