{"id":8349,"date":"2021-04-23T19:31:23","date_gmt":"2021-04-23T19:31:23","guid":{"rendered":"https:\/\/prwatech.in\/blog\/?p=8349"},"modified":"2024-04-13T05:57:29","modified_gmt":"2024-04-13T05:57:29","slug":"scala-primary-constructor","status":"publish","type":"post","link":"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/","title":{"rendered":"Scala &#8211; Primary Constructor"},"content":{"rendered":"\r\n<p><span data-sheets-root=\"1\" data-sheets-value=\"{&quot;1&quot;:2,&quot;2&quot;:&quot;Scala | Primary Constructor&quot;}\" data-sheets-userformat=\"{&quot;2&quot;:6145,&quot;3&quot;:{&quot;1&quot;:0,&quot;3&quot;:1},&quot;14&quot;:{&quot;1&quot;:3,&quot;3&quot;:1},&quot;15&quot;:&quot;Arial&quot;}\">Scala Primary Constructor<\/span><\/p>\r\n<p>&nbsp;<\/p>\r\n<p><a href=\"https:\/\/prwatech.com\/course\/apache-spark-training-course\">Scala<\/a> program which contains <a href=\"https:\/\/prwatech.in\/blog\/#\">only<\/a> one constructor then that constructor is known as <strong>Primary constructor<\/strong>.<\/p>\r\n<p>The parameters of the primary constructor are use to initialize the class&#8217;s fields. This means that class fields can be declare directly within the class body using constructor parameters, and these fields are accessible throughout the class.<\/p>\r\n<p>The primary constructor is invoked when an instance of the class is create. It executes the initialization code defined within the class body, such as initializing fields or executing expressions.<\/p>\r\n<p>Scala allows flexibility in defining the primary constructor:<\/p>\r\n<ul>\r\n<li>Parameters can be specified directly in the class definition, defining both the constructor parameters and corresponding fields.<\/li>\r\n<li>The primary constructor can include access modifiers (e.g., <code>val<\/code>, <code>var<\/code>, <code>private<\/code>) to specify visibility and mutability of fields.<\/li>\r\n<li>Auxiliary constructors (secondary constructors) can be defined using <code>def this(...)<\/code>, which must eventually call the primary constructor.<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<h3>syntax:-<\/h3>\r\n\r\n\r\n\r\n<p>class class name(parameter list) {<\/p>\r\n\r\n\r\n\r\n<p>\/\/statements<\/p>\r\n\r\n\r\n\r\n<p>}<\/p>\r\n\r\n\r\n\r\n<p><strong>use case 1:<\/strong><\/p>\r\n\r\n\r\n\r\n<p>scala&gt; class smartphone(val size:Int, val price:Double){<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 println(&#8220;Inside smartphone constructor&#8221;)<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 def desc = &#8220;smartphone price&#8221; + price + &#8220;is of size&#8221; + size<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 }<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"606\" height=\"86\" class=\"wp-image-8351\" src=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50.png\" alt=\"\" srcset=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50.png 606w, https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50-300x43.png 300w\" sizes=\"auto, (max-width: 606px) 100vw, 606px\" \/><\/figure>\r\n\r\n\r\n\r\n<p><strong>use case 2:<\/strong><\/p>\r\n\r\n\r\n\r\n<p>scala&gt; class Dog(val size:Int, val height:Double){<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 println(&#8220;Inside dog constructor&#8221;)<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 def desc = &#8220;Dog height&#8221; + height + &#8220;is of size&#8221; + size<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 }<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"606\" height=\"91\" class=\"wp-image-8352\" src=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-51.png\" alt=\"\" srcset=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-51.png 606w, https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-51-300x45.png 300w\" sizes=\"auto, (max-width: 606px) 100vw, 606px\" \/><\/figure>\r\n\r\n\r\n\r\n<p><strong>use case 3:<\/strong><\/p>\r\n\r\n\r\n\r\n<p>scala&gt; class Fruit(val name:String,val color:String, val weight:Double){<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 \u00a0println(&#8220;Inside dog constructor&#8221;)<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 \u00a0def desc = &#8220;Fruit name&#8221; + name + &#8220;is of color&#8221; + color + &#8220;and weight is&#8221; + weight<\/p>\r\n\r\n\r\n\r\n<p>\u00a0\u00a0\u00a0\u00a0 \u00a0}<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"606\" height=\"85\" class=\"wp-image-8353\" src=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-52.png\" alt=\"\" srcset=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-52.png 606w, https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-52-300x42.png 300w\" sizes=\"auto, (max-width: 606px) 100vw, 606px\" \/><\/figure>\r\n","protected":false},"excerpt":{"rendered":"<p>Scala Primary Constructor &nbsp; Scala program which contains only one constructor then that constructor is known as Primary constructor. The parameters of the primary constructor are use to initialize the class&#8217;s fields. This means that class fields can be declare directly within the class body using constructor parameters, and these fields are accessible throughout the [&hellip;]<\/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":[1064,1062,1066,1063,1058,1061,1050,1059,1060,1065],"class_list":["post-8349","post","type-post","status-publish","format-standard","hentry","category-scala","category-scala-modules-scala","tag-constructor-types","tag-constructors-scala","tag-constructors-use-cases-scala","tag-primary-constructor-example-scala","tag-primary-constructor-in-scala","tag-primary-constructor-scala","tag-scala-constructors","tag-scala-primary-constructor","tag-scala-primary-constructor-use-cases","tag-types-of-constructor-in-scala"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Scala Primary Constructor - Prwatech<\/title>\n<meta name=\"description\" content=\"Master Scala Primary Constructor - 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=\"Scala Primary Constructor - Prwatech\" \/>\n<meta property=\"og:description\" content=\"Master Scala Primary Constructor - 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\/scala-primary-constructor\/\" \/>\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=\"2021-04-23T19:31:23+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-04-13T05:57:29+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50.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=\"2 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\/scala-primary-constructor\/\",\"url\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/\",\"name\":\"Scala Primary Constructor - Prwatech\",\"isPartOf\":{\"@id\":\"https:\/\/prwatech.in\/blog\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50.png\",\"datePublished\":\"2021-04-23T19:31:23+00:00\",\"dateModified\":\"2024-04-13T05:57:29+00:00\",\"author\":{\"@id\":\"https:\/\/prwatech.in\/blog\/#\/schema\/person\/db90baff7744090b2288bbc98fea87f3\"},\"description\":\"Master Scala Primary Constructor - Dive deep with our expert instructors and comprehensive curriculum,enroll now.\",\"breadcrumb\":{\"@id\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/#primaryimage\",\"url\":\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50.png\",\"contentUrl\":\"https:\/\/prwatech.in\/blog\/wp-content\/uploads\/2021\/04\/image-50.png\",\"width\":606,\"height\":86},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/prwatech.in\/blog\/scala\/scala-modules-scala\/scala-primary-constructor\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/prwatech.in\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Scala &#8211; 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