{"id":8372,"date":"2021-04-24T08:12:56","date_gmt":"2021-04-24T08:12:56","guid":{"rendered":"https:\/\/prwatech.in\/blog\/?p=8372"},"modified":"2024-04-13T06:29:30","modified_gmt":"2024-04-13T06:29:30","slug":"scala-closure","status":"publish","type":"post","link":"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-closure\/","title":{"rendered":"Scala – Closure"},"content":{"rendered":"\r\n

A Guide to Scala’s Closures<\/span><\/h2>\r\n

 <\/p>\r\n

Closure<\/strong> is a function in scala<\/a>, it’s return value depends on one or more variable which is declared outside the function.<\/p>\r\n

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In Scala, procedures and functions are closely related concepts but have distinct characteristics based on their definitions and usage within the language.<\/p>\r\n

A function<\/strong> in Scala is a named block of code that takes zero or more input parameters and produces a result when invoked. Functions are defined using the def<\/code> keyword and explicitly specify a return type. They are first-class citizens in Scala, meaning they can be assigned to variables, passed as arguments, and returned from other functions. Functions in Scala always return a value, even if it’s Unit<\/code> (similar to void<\/code> in other languages).<\/p>\r\n

On the other hand, a procedure<\/strong> in Scala is a special kind of function that does not return a value explicitly. Procedures are defined using the def<\/code> keyword without specifying a return type (or specifying Unit<\/code> explicitly). Procedures are primarily used for their side effects, such as printing to the console or modifying mutable state, rather than computing and returning values.<\/p>\r\n

The distinction between functions and procedures highlights Scala’s functional programming capabilities and emphasizes the importance of clarity in side-effecting versus pure computations. While functions focus on producing results based on input parameters, procedures emphasize performing actions without necessarily returning a value. Understanding these differences is crucial for writing expressive and idiomatic Scala code.<\/p>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n\r\n\r\n\r\n

use case 1: <\/strong><\/h3>\r\n\r\n\r\n\r\n

object<\/strong> closure1 {<\/p>\r\n\r\n\r\n\r\n

\u00a0 def<\/strong> main(args: Array[String<\/em>]) {<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0 println( “multiplier(1) value = ” +\u00a0 multiplier(4) )<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0 println( “multiplier(2) value = ” +\u00a0 multiplier(5) )<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0 }<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0 var<\/strong> factor = 5<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0 val<\/strong> multiplier = (i:Int) => i * factor<\/p>\r\n\r\n\r\n\r\n

}<\/p>\r\n\r\n\r\n\r\n

\"\"<\/figure>\r\n\r\n\r\n\r\n

output<\/strong><\/p>\r\n\r\n\r\n\r\n

\"\"<\/figure>\r\n\r\n\r\n\r\n

use case 2:<\/strong><\/p>\r\n\r\n\r\n\r\n

object<\/strong> closure2 {<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 \/\/ Main method<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 def<\/strong> main(args: Array[String<\/em>])<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 {<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 println( “Final_Sum(1) value = ” + sum(1))<\/p>\r\n\r\n\r\n\r\n

\u00a0 \u00a0 \u00a0 \u00a0 2println( “Final_Sum(2) value = ” + sum(2))<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 println( “Final_Sum(3) value = ” + sum(3))<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 }<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 var<\/strong> a = 4<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 \/\/ define closure function<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 val<\/strong> sum = (b:Int) => b + a<\/p>\r\n\r\n\r\n\r\n

}<\/p>\r\n\r\n\r\n\r\n

\"\"<\/figure>\r\n\r\n\r\n\r\n

output<\/p>\r\n\r\n\r\n\r\n

\"\"<\/figure>\r\n\r\n\r\n\r\n

Here, In above program function\u00a0sum<\/strong>\u00a0is a closure function. var a = 4 is impure closure. the value of a is same and values of b is different.<\/p>\r\n\r\n\r\n\r\n

use case 3:<\/strong><\/p>\r\n\r\n\r\n\r\n

object<\/strong> closure3 {<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 \/\/ Main method<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 def<\/strong> main(args: Array[String<\/em>])<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 {<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 var<\/strong> employee = 30<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/\/ define closure function<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 val<\/strong> closure3 = (name: String<\/em>) => println(s”Company name is $name”+<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 s” and total no. of employees are $employee”)<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 closure3(“prwatech”)<\/p>\r\n\r\n\r\n\r\n

\u00a0\u00a0\u00a0 }<\/p>\r\n\r\n\r\n\r\n

}<\/p>\r\n\r\n\r\n\r\n

\"\"<\/figure>\r\n\r\n\r\n\r\n

output<\/p>\r\n\r\n\r\n\r\n

\"\"<\/figure>\r\n\r\n\r\n\r\n

Here, In above example\u00a0closure3<\/strong>\u00a0is a closure. var employee is mutable variable which can be change<\/a>.<\/p>\r\n\r\n\r\n\r\n

 <\/p>\r\n","protected":false},"excerpt":{"rendered":"

A Guide to Scala’s Closures   Closure is a function in scala, it’s return value depends on one or more variable which is declared outside the function. In Scala, procedures and functions are closely related concepts but have distinct characteristics based on their definitions and usage within the language. A function in Scala is a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[565,1698],"tags":[1088,1093,1091,1094,1090,1095,1092,1097,1089,1096],"class_list":["post-8372","post","type-post","status-publish","format-standard","hentry","category-scala","category-scala-modules-scala","tag-closure","tag-closure-example","tag-closure-function","tag-closure-function-in-scala","tag-closure-in-scala","tag-closure-scala-example","tag-closure-usecases-scala","tag-how-to-use-closure-in-scala","tag-scala-closure","tag-scala-closure-use-cases"],"acf":[],"yoast_head":"\nA Guide to Scala's Closures - Prwatech<\/title>\n<meta name=\"description\" content=\"Master A Guide to Scala's Closures - Dive deep with our expert instructors and comprehensive curriculum, Enroll now.\" \/>\n<meta name=\"robots\" content=\"noindex, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A Guide to Scala's Closures - 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