{"id":5700,"date":"2020-10-08T05:02:07","date_gmt":"2020-10-08T05:02:07","guid":{"rendered":"https:\/\/prwatech.in\/blog\/?p=5700"},"modified":"2024-04-12T06:14:33","modified_gmt":"2024-04-12T06:14:33","slug":"list-in-scala-programming-language-guide-to-to-scala-collections","status":"publish","type":"post","link":"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/list-in-scala-programming-language-guide-to-to-scala-collections\/","title":{"rendered":"Scala – List"},"content":{"rendered":"\r\n

Creating a List in Scala<\/span><\/h2>\r\n

List:<\/h3>\r\n\r\n\r\n\r\n

All the elements of a list have the same type but there are two important differences. First, lists are immutable, which means elements of a list cannot be changed by assignment. Second, lists represent a linked list whereas arrays are flat.<\/p>\r\n

In Scala, lists are immutable collections that represent ordered sequences of elements. To create a list in Scala, you can use the List<\/code> companion object to instantiate a new list with specified elements. Lists in Scala are implemented as linked lists, where each element is stored in a node that points to the next element in the list.<\/p>\r\n

Here’s how you can create a list in Scala:<\/p>\r\n

\/\/ Creating a list of integers
val numbers: List[Int] = List(1, 2, 3, 4, 5)<\/p>\r\n

\/\/ Creating a list of strings
val fruits: List[String] = List(“apple”, “banana”, “orange”)<\/p>\r\n

 <\/p>\r\n\r\n\r\n\r\n

Run the following commands:<\/p>\r\n\r\n\r\n\r\n

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

\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 By default immutable<\/p>\r\n\r\n\r\n\r\n

\u00a0They do not maintain order<\/p>\r\n\r\n\r\n\r\n

\u00b7\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 List can\u2019t be accessed by their Index.<\/p>\r\n\r\n\r\n\r\n

1. Example program to show usage of the basic List operational methods:<\/p>\r\n\r\n\r\n\r\n

package Collection\r\nobject List1 {\r\n\r\ndefmain(args: Array[String]) {\r\nval lang1 = \"Python\" :: (\"Machine Learning\" ::( \"Sql\":: <\/pre>\r\n
1Nil<\/em><\/p>\r\n
))\r\nval num = <\/pre>\r\n
Nil println<\/em><\/p>\r\n
( \"Best of Programming Language : \" + lang1.head )\r\n\r\n<\/pre>\r\n
println<\/em><\/p>\r\n
( \"Other Programming Language : \" + lang1.tail )\r\n\r\n<\/pre>\r\n
2println<\/em><\/p>\r\n
( \"Check if Set is empty : \" + lang1.isEmpty )\r\n\r\n<\/pre>\r\n
println<\/em><\/p>\r\n
( \"Check if num is empty : \" + num.<\/pre>\r\n
isEmpty<\/em><\/p>\r\n
)\r\n\u00a0 }\r\n}<\/pre>\r\n\r\n\r\n\r\n
\"\"<\/figure>\r\n\r\n\r\n\r\n
2. Example program to show usage of the List with respect to concatenation:<\/p>\r\n\r\n\r\n\r\n
package Collection\r\nobject List2 {\r\n\r\ndefmain(args: Array[String]) {\r\n\r\nval lang1 = \"Python\" :: (\"DataScience\"::(\"Sql\":: <\/pre>\r\n
2Nil<\/em><\/p>\r\n
))\r\n\r\nval lang2 = \"Hadoop\" :: (\"Scala\" :: (\"AWS\":: <\/pre>\r\n
Nil<\/em><\/p>\r\n
))\r\n\r\n\/\/ using two Lists with ::: as operator\r\n\r\nvar lang = lang1 ::: lang2\r\n\r\n<\/pre>\r\n
println<\/em><\/p>\r\n
( \"lang1 ::: lang2 : \" + lang )\r\n\r\n\/\/ using two Lists with Set .:::() method\r\n\r\nlang = lang1.:::(lang2)\r\n\r\n<\/pre>\r\n
3println<\/em><\/p>\r\n
( \"lang1.:::(lang2) : \" + lang )\r\n\r\n\/\/ passing two lists as arguments\r\n\r\nlang = <\/pre>\r\n
List<\/em><\/p>\r\n
.concat(lang1, lang2)\r\n\r\n<\/pre>\r\n
println<\/em><\/p>\r\n
( \"List.concat(lang1, lang2) : \" + lang\u00a0 )\r\n\r\n\u00a0 }\r\n}<\/pre>\r\n\r\n\r\n\r\n
\"\"<\/figure>\r\n\r\n\r\n\r\n
3. Program to create a list with zero or more copies of the same element using\u00a0List.fill()\u00a0method.<\/p>\r\n\r\n\r\n\r\n
package Collection\r\nobject List3 {\r\ndefmain(args: Array[String]) {\r\n\r\n\/\/ Repeatedly prints PrwaTech four times.\r\n\r\nval center = <\/pre>\r\n
List<\/em><\/p>\r\n
.fill(4)(\"PrwaTech\")\r\n<\/pre>\r\n
println<\/em><\/p>\r\n
( \"Learning Center : \" + center )\r\n\r\n\/\/ Repeatedly prints 6, 12 times.\r\n\r\nval num = <\/pre>\r\n
List<\/em><\/p>\r\n
.fill(12)(6)\r\n<\/pre>\r\n
println<\/em><\/p>\r\n
( \"num : \" + num\u00a0 )\r\n\u00a0 }\r\n}\r\n<\/pre>\r\n\r\n\r\n\r\n
\"\"<\/figure>\r\n\r\n\r\n\r\n
4. Program to Sort and reverse all elements of the list.<\/p>\r\n\r\n\r\n\r\n
package Collection\r\nobject List4 {\r\n\r\ndefmain(args: Array[String]) {\r\n\r\nval lang1 = \"Python\" :: (\"Hadoop\" :: (\"DataScience\" :: (\"Sql\" :: (\"AWS\" :: (\"Scala\" :: <\/pre>\r\n
Nil<\/em><\/p>\r\n
)))))\r\n\r\nval lang2 = lang1.sorted\r\n\r\n<\/pre>\r\n
println<\/em><\/a><\/p>\r\n
(\"List Before Sorting : \" + lang1)\r\n\r\n<\/pre>\r\n
3println<\/em><\/p>\r\n
(\"List After Sorting : \" + lang2)\r\n\r\n<\/pre>\r\n
println<\/em><\/a><\/p>\r\n
(\"Before reversing Lang List : \" + lang2)\r\n\r\n<\/pre>\r\n
4println<\/em><\/p>\r\n
(\"After reversing Lang List : \" + lang2.reverse)\r\n\u00a0 }\r\n}<\/pre>\r\n\r\n\r\n\r\n
\"\"<\/figure>\r\n
Creating a List in Scala<\/span><\/p>\r\n","protected":false},"excerpt":{"rendered":"
Creating a List in Scala List: All the elements of a list have the same type but there are two important differences. First, lists are immutable, which means elements of a list cannot be changed by assignment. Second, lists represent a linked list whereas arrays are flat. In Scala, lists are immutable collections that represent […]<\/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":[1986,1988,1987],"class_list":["post-5700","post","type-post","status-publish","format-standard","hentry","category-scala","category-scala-modules-scala","tag-guide-to-to-scala-collections","tag-scala-lists","tag-the-list-class-scala-book"],"acf":[],"yoast_head":"\nCreating a List in Scala - Prwatech<\/title>\n<meta name=\"description\" content=\"Master Creating a List in Scala - 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=\"Creating a List in Scala - Prwatech\" \/>\n<meta property=\"og:description\" content=\"Master Creating a List in Scala - Dive deep with our expert instructors and comprehensive curriculum, Enroll now.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/list-in-scala-programming-language-guide-to-to-scala-collections\/\" \/>\n<meta property=\"og:site_name\" content=\"Prwatech\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/prwatech.in\/\" \/>\n<meta property=\"article:published_time\" content=\"2020-10-08T05:02:07+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-04-12T06:14:33+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2020\/12\/image-32.png\" \/>\n<meta name=\"author\" content=\"Prwatech\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@Eduprwatech\" \/>\n<meta name=\"twitter:site\" content=\"@Eduprwatech\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Prwatech\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/list-in-scala-programming-language-guide-to-to-scala-collections\/\",\"url\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/list-in-scala-programming-language-guide-to-to-scala-collections\/\",\"name\":\"Creating a List in Scala - 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