{"id":4804,"date":"2025-11-28T12:27:21","date_gmt":"2025-11-28T11:27:21","guid":{"rendered":"https:\/\/sutilweb.eu\/?page_id=4804"},"modified":"2025-11-28T12:27:22","modified_gmt":"2025-11-28T11:27:22","slug":"03-variables-en-php","status":"publish","type":"page","link":"https:\/\/sutilweb.eu\/index.php\/lenguajes\/php\/php-practico\/03-variables-en-php\/","title":{"rendered":"03. Variables en PHP"},"content":{"rendered":"\n<p>En este cap\u00edtulo vamos a ver que son las variables y para que sirven. Mientras vamos desarrollando nuestra aplicaci\u00f3n vamos a tener la necesidad de almacenar informaci\u00f3n en alguna parte. Ese espacio de lugar donde nosotros queremos almacenar esa informaci\u00f3n se le conoce como variable.<\/p>\n\n\n\n<p>Variable es el espacio de memoria que utilizamos para almacenar datos que utilizaremos de manera repetitiva en nuestra aplicaci\u00f3n. Igual que en otros lenguajes de programaci\u00f3n, en PHP utilizamos identificadores para definir una variable. Un identificador viene a ser el nombre que nosotros vamos a darle a esta variable, y gracias a ese nombre vamos a poder recuperar luego la informaci\u00f3n de esta variable.<\/p>\n\n\n\n<p><strong>Ejm<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">$nota = 10;<\/pre>\n\n\n\n<p>Todos los identificadores de variables en PHP comienzan con el s\u00edmbolo del d\u00f3lar (<em><strong>$<\/strong><\/em>). Para asignarle un valor a la variable utilizamos el s\u00edmbolo igual (=).<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Caracter\u00edsticas de las variables<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>El nombre de las variables debe comenzar con el s\u00edmbolo de d\u00f3lar.<\/li>\n\n\n\n<li>Dicho nombre es sensible a may\u00fasculas y min\u00fasculas.<\/li>\n\n\n\n<li>Tipado d\u00e9bil: las variables no necesitan ser declaradas antes de ser usadas.<\/li>\n\n\n\n<li>El nombre de las variables s\u00f3lo puede contener caracteres alfanum\u00e9ricos, y no pueden llevar espacios.<\/li>\n\n\n\n<li>Podemos usar varios estilos de escritura:\n<ul class=\"wp-block-list\">\n<li><strong>Snake Case<\/strong>: <em><strong>$mi_variable<\/strong><\/em><\/li>\n\n\n\n<li><strong>Upper Camel Case<\/strong>: <em><strong>$MiVariable<\/strong><\/em><\/li>\n\n\n\n<li><strong>Lower Camel Case<\/strong><em><strong>: $miVariable<\/strong><\/em><\/li>\n\n\n\n<li><strong>Kebab Case<\/strong>: <em><strong>$mi-variable<\/strong><\/em><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p><strong>Nota<\/strong>: Se suelen utilizar para variables los estilos Snake Case o Lower Camel Case.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Comillas dobles o simples<\/h2>\n\n\n\n<p>Cuando utilizamos comillas dobles no necesitamos utilizar la concatenaci\u00f3n, poniendo el nombre de la variable ya nos devuelve su valor, en el caso de las comillas simples s\u00ed que necesitar\u00edamos concatenar.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>En este cap\u00edtulo vamos a ver que son las variables y para que sirven. Mientras vamos desarrollando nuestra aplicaci\u00f3n vamos [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":4518,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-4804","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"Sutil Web","author_link":"https:\/\/sutilweb.eu\/index.php\/author\/sutilweb\/"},"uagb_comment_info":0,"uagb_excerpt":"En este cap\u00edtulo vamos a ver que son las variables y para que sirven. Mientras vamos desarrollando nuestra aplicaci\u00f3n vamos [&hellip;]","_links":{"self":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/4804","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/comments?post=4804"}],"version-history":[{"count":18,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/4804\/revisions"}],"predecessor-version":[{"id":4824,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/4804\/revisions\/4824"}],"up":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/4518"}],"wp:attachment":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/media?parent=4804"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}