![\"\"](\"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/public\/phshighercomputingscience\/uploads\/sites\/10042\/2022\/05\/24101822\/Screenshot-2022-05-24-101803-300x152.png\")
<\/p>\n
- \n
- Formal parameters contains the placeholder of the actual parameters .<\/span><\/strong><\/li>\n
- Any changes to the formal parameters are automatically made to the actual parameter.<\/span><\/strong><\/li>\n
- The Actual parameters contain the value<\/span><\/strong><\/li>\n<\/ul>\n
Passing Parameters by Reference\u00a0 and by Value<\/h2>\n
Parameter Passing by Reference<\/strong><\/h3>\n
Parameter passing by reference<\/strong> is used\u00a0 when the value being passed in is to be updated and passes back out again.<\/strong> (The variable itself is passed into the subprogram so that any changes to the variable will change the variable.<\/p>\n
If a programmer passes a parameter by reference, then the subprogram or function has\u00a0<\/span>direct access to the memory location<\/span><\/strong>\u00a0holding the value of the variable.<\/span><\/p>\n
This means that any change to the value during the execution of the subprogram would apply when the variable was next used in the main program.<\/span><\/p>\n
Parameter Passing by Value<\/h3>\n
Parameter passing by value <\/b>is used\u00a0 when a value is passed into a subprogram but does not require to be passed out<\/strong>. (The subprogram makes a copy of the variable so that any changes to the copy of the variable will not change the variable.<\/p>\n
If a programmer passes a parameter by value, then a\u00a0<\/span>temporary second copy of the value of the variable is made and held in RAM<\/span><\/strong>.<\/span><\/p>\n
This copy can be changed within a subprogram but the change would not affect the original value held in the main program\u2019s local variable.<\/span><\/p>\n
Drawback<\/span><\/h3>\n
The main drawback is the increased demand on RAM.\u00a0 <\/span>As well as having to store the original value of the local variable, it is also necessary to store a second copy in main memory as well.<\/span><\/p>\n
Advantage<\/span><\/h3>\n
The main advantage is that the value of the original local variable is protected from accidental or unnecessary change.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"
Parameters A\u00a0 parameter is a variable or value that is passed into and\/or out of a subprogram.\u00a0 There are two types of parameters. The formal parameters are a placeholder for the actual parameter The actual parameters are the values passed into the subprogram Formal parameters contains the placeholder of the actual parameters . Any changes […]<\/p>\n","protected":false},"author":79984,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-220","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/pages\/220","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/users\/79984"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/comments?post=220"}],"version-history":[{"count":9,"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/pages\/220\/revisions"}],"predecessor-version":[{"id":352,"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/pages\/220\/revisions\/352"}],"wp:attachment":[{"href":"https:\/\/blogs.glowscotland.org.uk\/glowblogs\/phshighercomputingscience\/wp-json\/wp\/v2\/media?parent=220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- Any changes to the formal parameters are automatically made to the actual parameter.<\/span><\/strong><\/li>\n