{"id":2511,"date":"2013-05-21T14:33:45","date_gmt":"2013-05-21T14:33:45","guid":{"rendered":"http:\/\/www.webninjataylor.com\/library\/?p=2511"},"modified":"2014-06-24T21:11:17","modified_gmt":"2014-06-24T21:11:17","slug":"using-dispatch-tables-to-avoid-conditionals-in-javascript","status":"publish","type":"post","link":"https:\/\/webninjataylor.com\/library\/using-dispatch-tables-to-avoid-conditionals-in-javascript\/","title":{"rendered":"Using Dispatch Tables to Avoid Conditionals in JavaScript"},"content":{"rendered":"<pre>function processUserInput(command) {\r\n    switch (command) {\r\n        case \"north\":\r\n            movePlayer(\"north\");\r\n            break;\r\n        case \"east\":\r\n            movePlayer(\"east\");\r\n            break;\r\n        case \"south\":\r\n            movePlayer(\"south\");\r\n            break;\r\n        case \"west\":\r\n            movePlayer(\"west\");\r\n            break;\r\n        case \"look\":\r\n            describeLocation();\r\n            break;\r\n        case \"backpack\":\r\n            showBackpack();\r\n            break;\r\n    }\r\n}<\/pre>\n<p>Can be turned into&#8230;<\/p>\n<pre>var commandTable = {\r\n    north:    function() { movePlayer(\"north\"); },\r\n    east:     function() { movePlayer(\"east\");  },\r\n    south:    function() { movePlayer(\"south\"); },\r\n    west:     function() { movePlayer(\"west\");  },\r\n    look:     describeLocation,\r\n    backpack: showBackpack\r\n}\r\n\r\nfunction processUserInput(command) {\r\n    commandTable[command]();\r\n}<\/pre>\n<p>Where the commandTable object&#8217;s properties are accessible via bracketed notation, so <span class=\"code\">commanTable[command]<\/span> is like saying <span class=\"code\">commandTable.north<\/span> for example.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>function processUserInput(command) { switch (command) { case &#8220;north&#8221;: movePlayer(&#8220;north&#8221;); break; case &#8220;east&#8221;: movePlayer(&#8220;east&#8221;); break; case &#8220;south&#8221;: movePlayer(&#8220;south&#8221;); break; case &#8220;west&#8221;: movePlayer(&#8220;west&#8221;); break; case &#8220;look&#8221;: describeLocation(); break; case &#8220;backpack&#8221;: showBackpack(); break; } } Can be turned into&#8230; var commandTable = { north: function() { movePlayer(&#8220;north&#8221;); }, east: function() { movePlayer(&#8220;east&#8221;); }, south: function() { movePlayer(&#8220;south&#8221;); }, [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[144],"tags":[9],"class_list":["post-2511","post","type-post","status-publish","format-standard","hentry","category-web-shots","tag-javascript"],"_links":{"self":[{"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/posts\/2511","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/comments?post=2511"}],"version-history":[{"count":4,"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/posts\/2511\/revisions"}],"predecessor-version":[{"id":3358,"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/posts\/2511\/revisions\/3358"}],"wp:attachment":[{"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/media?parent=2511"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/categories?post=2511"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/webninjataylor.com\/library\/wp-json\/wp\/v2\/tags?post=2511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}