{"id":34,"date":"2016-09-27T01:54:59","date_gmt":"2016-09-27T01:54:59","guid":{"rendered":"http:\/\/52.201.184.187\/?p=34"},"modified":"2018-01-02T12:48:30","modified_gmt":"2018-01-02T12:48:30","slug":"javascript-falsy-values","status":"publish","type":"post","link":"http:\/\/52.201.184.187\/blog\/javascript\/javascript-falsy-values\/","title":{"rendered":"Javascript falsy values"},"content":{"rendered":"<p>Una de las particularidades con los que nos encontramos quienes empezamos a meternos con Javascript son los \u00abfalsy values\u00bb. Estos son los valores que el lenguaje toma como FALSO al ser utilizados como booleanos. Cualquier otro valor que utilicemos nos va a dar true. Es un mecanismo similar al que usa C con los n\u00fameros, pero m\u00e1s amplio.<\/p>\n<p>Los valores que dan falso son:<\/p>\n<ul>\n<li><strong>false<\/strong><\/li>\n<li><strong>0 (cero)<\/strong><\/li>\n<li><strong>\u00ab\u00bb (vac\u00edo)<\/strong><\/li>\n<li><strong>null<\/strong><\/li>\n<li><strong>undefined<\/strong><\/li>\n<li><strong>NaN<\/strong><\/li>\n<\/ul>\n<p>Otra particularidad que tiene este lenguaje es que <strong>si hacemos un \u00abOR\u00bb, en el caso de dar true, este nos retorna el valor que convirti\u00f3 en verdadero el if<\/strong>. Por ejemplo: var saludo = 0 || \u00abHola\u00bb;\u00a0 nos guardar\u00e1 \u00abHola\u00bb en la variable saludo. Esto es particularmente \u00fatil si queremos dar valores por default a una variable. Ejemplo: var foo= otraVariable ||{};<\/p>\n<p>Les dejo un proyectito ilustrando estas situaciones <a href=\"https:\/\/bitbucket.org\/etebes\/js-falsy-values\/\">https:\/\/bitbucket.org\/etebes\/js-falsy-values\/<\/a><\/p>\n<p>Post basado en este blog:<a href=\"https:\/\/www.sitepoint.com\/javascript-truthy-falsy\/\"> https:\/\/www.sitepoint.com\/javascript-truthy-falsy\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Una de las particularidades con los que nos encontramos quienes empezamos a meternos con Javascript son los \u00abfalsy values\u00bb. Estos son los valores que el lenguaje toma como FALSO al ser utilizados como booleanos. Cualquier otro valor que utilicemos nos va a dar true. Es un mecanismo similar al que usa C con los n\u00fameros,\u2026 <span class=\"read-more\"><a href=\"http:\/\/52.201.184.187\/blog\/javascript\/javascript-falsy-values\/\">Leer m\u00e1s &raquo;<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[28,7],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v17.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Javascript falsy values - Desarrollo \u00c1gil<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"http:\/\/52.201.184.187\/blog\/javascript\/javascript-falsy-values\/\" \/>\n<meta property=\"og:locale\" content=\"es_ES\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Javascript falsy values - Desarrollo \u00c1gil\" \/>\n<meta property=\"og:description\" content=\"Una de las particularidades con los que nos encontramos quienes empezamos a meternos con Javascript son los \u00abfalsy values\u00bb. 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