{"id":6405,"date":"2023-01-24T04:28:53","date_gmt":"2023-01-24T04:28:53","guid":{"rendered":"https:\/\/studysection.com\/blog\/?p=6405"},"modified":"2023-02-02T12:04:07","modified_gmt":"2023-02-02T12:04:07","slug":"singleton-pattern-in-php","status":"publish","type":"post","link":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/","title":{"rendered":"Singleton pattern in PHP"},"content":{"rendered":"<p>In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible. The Singleton design pattern restricts classes to a single object.<\/p>\n<h2>How to use it?<\/h2>\n<p>We need to create a Singleton class:<\/p>\n<ol>\n<li>static member variable: This acts as a placeholder for an instance of the class.<\/li>\n<li>Private constructor: A private constructor prevents a class from being instantiated directly.<\/li>\n<li>Prevent objects from being cloned by modifying the clone wizard.<\/li>\n<li>Create a static method for global access.<\/li>\n<\/ol>\n<p><code>&lt;?php<br \/>\nclass Singleton {<br \/>\nprivate static $_instance = null;<br \/>\n\/* Prevent direct instantiation of a class. *\/<br \/>\nprivate function __construct() {}<br \/>\n\/* Prevent object cloning.  *\/<br \/>\nprivate function __clone() {}<br \/>\n\/* Static method to provide global access point. *\/<br \/>\npublic static function getInstance()<br \/>\n{<br \/>\nif(self::$_instance == null) {<br \/>\nself::$_instance = new Singleton();<br \/>\n}<br \/>\nreturn self::$_instance;<br \/>\n}<br \/>\n\/* Prevent unserializing of singleton instance *\/<br \/>\nprivate function __wakeup() {}<br \/>\n}<br \/>\n$obj1 = Singleton::getInstance();<br \/>\n$obj2 = Singleton::getInstance();<br \/>\nvar_dump($obj1);<br \/>\nvar_dump($obj2);<br \/>\n?&gt;<\/code><\/p>\n<p>In this example, I created two variables that represent the same object. The first time the getInstance() method is called, it will create a new object. Any call after that will just return the design object.<br \/>\nCreate a simple database connection class using the Singleton Design pattern.<\/p>\n<p><code>&lt;?php<br \/>\nclass DatabaseConnection {<br \/>\nprivate $_connection;<br \/>\nprivate static $_instance;<br \/>\nprivate $_dbhost = \"localhost\"<br \/>\nprivate $_dbusername = \"root\";<br \/>\nprivate $_dbpassword = \"123456\";<br \/>\nprivate $_dbdatabase = \"ams_dev\";<br \/>\nprivate function __construct() {<br \/>\n$this-&gt;_connection = new mysqli($this-&gt;_dbhost, $this-&gt;_dbusername,<br \/>\n$this-&gt;_dbpassword, $this-&gt;_dbdatabase);<br \/>\nif(mysqli_connect_error()) {<br \/>\ntrigger_error(\"Connection Failed\" . mysqli_connect_error(),<br \/>\nE_USER_ERROR);<br \/>\n}}<br \/>\npublic static function getInstance() {<br \/>\nif(self::$_instance == null) {<br \/>\nself::$_instance = new self();<br \/>\n}<br \/>\nreturn self::$_instance;<br \/>\n}<br \/>\nprivate function __clone(){}<br \/>\npublic function getConnection(){<br \/>\nreturn $this-&gt;_connection;<br \/>\n}}<\/code><\/p>\n<p>This design pattern is very useful when we require one instance of a class for the entire lifecycle of a request in a web application. Apply this design pattern to your logger class, configuration class, etc., where only one global entry point is needed.<\/p>\n<p><small><em>Being the most extensively used JavaScript library, a <a href=\"https:\/\/www.studysection.com\/jquery-3.x-advanced\">jQuery Certification<\/a> will add enormous value to your skill-set. jQuery provides various functionalities to the developer in order to develop complex applications with ease and efficiency.<\/em><\/small><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is<\/p>\n","protected":false},"author":1,"featured_media":6406,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[200,747],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Singleton pattern in PHP - StudySection Blog<\/title>\n<meta name=\"description\" content=\"In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Singleton pattern in PHP - StudySection Blog\" \/>\n<meta property=\"og:description\" content=\"In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog Posts on famous people, innovations and educational topics\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/studysection\" \/>\n<meta property=\"article:published_time\" content=\"2023-01-24T04:28:53+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-02-02T12:04:07+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/studysection.com\/blog\/wp-content\/uploads\/2023\/01\/Singleton1.png\" \/>\n\t<meta property=\"og:image:width\" content=\"300\" \/>\n\t<meta property=\"og:image:height\" content=\"200\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"admin-studysection-blog\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@studysection\" \/>\n<meta name=\"twitter:site\" content=\"@studysection\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin-studysection-blog\" \/>\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\":\"Article\",\"@id\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\"},\"author\":{\"name\":\"admin-studysection-blog\",\"@id\":\"https:\/\/studysection.com\/blog\/#\/schema\/person\/db367e2c29a12d1808fb1979edb3d402\"},\"headline\":\"Singleton pattern in PHP\",\"datePublished\":\"2023-01-24T04:28:53+00:00\",\"dateModified\":\"2023-02-02T12:04:07+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\"},\"wordCount\":215,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/studysection.com\/blog\/#organization\"},\"keywords\":[\"php\",\"Singleton\"],\"articleSection\":[\"Learn and Grow\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\",\"url\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\",\"name\":\"Singleton pattern in PHP - StudySection Blog\",\"isPartOf\":{\"@id\":\"https:\/\/studysection.com\/blog\/#website\"},\"datePublished\":\"2023-01-24T04:28:53+00:00\",\"dateModified\":\"2023-02-02T12:04:07+00:00\",\"description\":\"In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible.\",\"breadcrumb\":{\"@id\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/studysection.com\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Singleton pattern in PHP\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/studysection.com\/blog\/#website\",\"url\":\"https:\/\/studysection.com\/blog\/\",\"name\":\"Blog Posts on famous people, innovations and educational topics\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/studysection.com\/blog\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/studysection.com\/blog\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/studysection.com\/blog\/#organization\",\"name\":\"StudySection\",\"url\":\"https:\/\/studysection.com\/blog\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/studysection.com\/blog\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/studysection.com\/blog\/wp-content\/uploads\/2021\/10\/studySection-logo.png\",\"contentUrl\":\"https:\/\/studysection.com\/blog\/wp-content\/uploads\/2021\/10\/studySection-logo.png\",\"width\":920,\"height\":440,\"caption\":\"StudySection\"},\"image\":{\"@id\":\"https:\/\/studysection.com\/blog\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/studysection\",\"https:\/\/twitter.com\/studysection\",\"https:\/\/www.instagram.com\/study.section\/\",\"https:\/\/www.linkedin.com\/company\/studysection\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/studysection.com\/blog\/#\/schema\/person\/db367e2c29a12d1808fb1979edb3d402\",\"name\":\"admin-studysection-blog\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/studysection.com\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/054ac87a6874df1932004239cd8eab36?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/054ac87a6874df1932004239cd8eab36?s=96&d=mm&r=g\",\"caption\":\"admin-studysection-blog\"},\"url\":\"https:\/\/studysection.com\/blog\/author\/admin-studysection-blog\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Singleton pattern in PHP - StudySection Blog","description":"In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/","og_locale":"en_US","og_type":"article","og_title":"Singleton pattern in PHP - StudySection Blog","og_description":"In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible.","og_url":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/","og_site_name":"Blog Posts on famous people, innovations and educational topics","article_publisher":"https:\/\/www.facebook.com\/studysection","article_published_time":"2023-01-24T04:28:53+00:00","article_modified_time":"2023-02-02T12:04:07+00:00","og_image":[{"width":300,"height":200,"url":"https:\/\/studysection.com\/blog\/wp-content\/uploads\/2023\/01\/Singleton1.png","type":"image\/png"}],"author":"admin-studysection-blog","twitter_card":"summary_large_image","twitter_creator":"@studysection","twitter_site":"@studysection","twitter_misc":{"Written by":"admin-studysection-blog","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#article","isPartOf":{"@id":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/"},"author":{"name":"admin-studysection-blog","@id":"https:\/\/studysection.com\/blog\/#\/schema\/person\/db367e2c29a12d1808fb1979edb3d402"},"headline":"Singleton pattern in PHP","datePublished":"2023-01-24T04:28:53+00:00","dateModified":"2023-02-02T12:04:07+00:00","mainEntityOfPage":{"@id":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/"},"wordCount":215,"commentCount":0,"publisher":{"@id":"https:\/\/studysection.com\/blog\/#organization"},"keywords":["php","Singleton"],"articleSection":["Learn and Grow"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/","url":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/","name":"Singleton pattern in PHP - StudySection Blog","isPartOf":{"@id":"https:\/\/studysection.com\/blog\/#website"},"datePublished":"2023-01-24T04:28:53+00:00","dateModified":"2023-02-02T12:04:07+00:00","description":"In the Singleton Design Pattern, we guarantee that there is only one instance of a class and that it is globally accessible.","breadcrumb":{"@id":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/studysection.com\/blog\/singleton-pattern-in-php\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/studysection.com\/blog\/"},{"@type":"ListItem","position":2,"name":"Singleton pattern in PHP"}]},{"@type":"WebSite","@id":"https:\/\/studysection.com\/blog\/#website","url":"https:\/\/studysection.com\/blog\/","name":"Blog Posts on famous people, innovations and educational topics","description":"","publisher":{"@id":"https:\/\/studysection.com\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/studysection.com\/blog\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/studysection.com\/blog\/#organization","name":"StudySection","url":"https:\/\/studysection.com\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/studysection.com\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/studysection.com\/blog\/wp-content\/uploads\/2021\/10\/studySection-logo.png","contentUrl":"https:\/\/studysection.com\/blog\/wp-content\/uploads\/2021\/10\/studySection-logo.png","width":920,"height":440,"caption":"StudySection"},"image":{"@id":"https:\/\/studysection.com\/blog\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/studysection","https:\/\/twitter.com\/studysection","https:\/\/www.instagram.com\/study.section\/","https:\/\/www.linkedin.com\/company\/studysection"]},{"@type":"Person","@id":"https:\/\/studysection.com\/blog\/#\/schema\/person\/db367e2c29a12d1808fb1979edb3d402","name":"admin-studysection-blog","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/studysection.com\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/054ac87a6874df1932004239cd8eab36?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/054ac87a6874df1932004239cd8eab36?s=96&d=mm&r=g","caption":"admin-studysection-blog"},"url":"https:\/\/studysection.com\/blog\/author\/admin-studysection-blog\/"}]}},"views":273,"_links":{"self":[{"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/posts\/6405"}],"collection":[{"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/comments?post=6405"}],"version-history":[{"count":2,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/posts\/6405\/revisions"}],"predecessor-version":[{"id":6431,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/posts\/6405\/revisions\/6431"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/media\/6406"}],"wp:attachment":[{"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/media?parent=6405"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/categories?post=6405"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/studysection.com\/blog\/wp-json\/wp\/v2\/tags?post=6405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}