{"id":8059,"date":"2019-11-29T11:00:07","date_gmt":"2019-11-29T02:00:07","guid":{"rendered":"https:\/\/www.gigas-jp.com\/appnews\/?p=8059"},"modified":"2019-11-29T12:32:33","modified_gmt":"2019-11-29T03:32:33","slug":"lodash-js-part-2chaining-and-has-method","status":"publish","type":"post","link":"https:\/\/www.gigas-jp.com\/appnews\/archives\/8059","title":{"rendered":"Lodash Js Part 2(Chaining and has method)"},"content":{"rendered":"\n<p>Today I will talk about chaining functions and has method.<\/p>\n\n\n\n<h3>Chaining<\/h3>\n\n\n\n<h4><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#without-chaining\"><\/a>Without Chaining<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>var data1 = [10, 15, 20, 25, 15];\n\nvar data2 = _.filter(data1, function(item){ return item % 10 === 5 });\n\/\/ data2 now contains [15, 25, 15]\n\nvar data3 = _.uniq(data2);\n\/\/ data3 now contains [15, 25]\n\nvar data4 = _.map(data3, function(item){ return item + 1 });\n\/\/ data4 now contains [16, 26]\n<\/code><\/pre>\n\n\n\n<h4><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#with-chaining\"><\/a>With Chaining<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>var data1 = [10, 15, 20, 25, 15];\n\nvar data4 = _(data1)\n    .filter(function(item){ return item % 10 === 5 })\n    .uniq()\n    .map(function(item){ return item + 1 })\n    .value();\n\/\/ data4 now contains [16, 26]\n<\/code><\/pre>\n\n\n\n<ul><li>The chaining is more efficient.<\/li><li>no intermediate results are created.<\/li><\/ul>\n\n\n\n<h3><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#slight-changes-for-explicit-chain--implicit-chain\"><\/a>Slight Changes for&nbsp;<code>Explicit Chain<\/code>&nbsp;&amp;&nbsp;<code>Implicit Chain<\/code><\/h3>\n\n\n\n<h4><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#explicit-chaining\"><\/a>Explicit chaining<\/h4>\n\n\n\n<h4><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#still-need-to-unwrap-the-result-with-value\"><\/a>Still need to unwrap the result with .value().<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>var data = [1, 5, 10, 15, 5, 10, 1, 20];\n\nvar unqSum = _.chain(data)\n   .uniq()\n   .sum()       \n   .value();   \nresult is 51\n<\/code><\/pre>\n\n\n\n<h3><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#implicit-chaining\"><\/a>Implicit chaining<\/h3>\n\n\n\n<h4><a href=\"https:\/\/github.com\/HlaingTinHtun\/Lodash_Js_Research_Development\/blob\/master\/basic_workflows\/chaining.md#the-unwrapping-of-the-single-value-is-implied-there-is-no-need-to-call-value\"><\/a>The &#8220;unwrapping&#8221; of the single value is implied. (there is no need to call .value().)<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>var data = [1, 5, 10, 15, 5, 10, 1, 20];\n\nvar unqSum = _(data)\n    .uniq()\n    .sum();  \n    \n    \/\/result is 51<\/code><\/pre>\n\n\n\n<h3>has<\/h3>\n\n\n\n<ul><li>Determine if an object has (or contains) a key.<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>var obj = {\n  data1: 2,\n  data2: 3,\n  data3: {\n    data3_1:40,\n    data3_2:{\n      data3_2_1:500\n    }\n  }\n};\n\nvar res1 = _.has(obj, \"data1\");          \/\/ true\nvar res2 = _.has(obj, \"data1.data2\");        \/\/ false\nvar res3 = _.has(obj, \"data3\");          \/\/ true\nvar res4 = _.has(obj, \"data3.data3_2\");       \/\/ true\nvar res5 = _.has(obj, \"data3.res3_2_1\");      \/\/ false\nvar res6 = _.has(obj, \"data3.data3_1.data3_2_1\");   \/\/ false\nvar res7 = _.has(obj, \"data3.data3_2.data3_2_1\");   \/\/ true\n<\/code><\/pre>\n\n\n\n<ul><li>Arrays can be used to split up parts.<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>var res8 = _.has(obj, [\"data1\", \"data2\"]);   \/\/ false, same as res2\nvar res9 = _.has(obj, [\"data3\", \"data3_2\"]);  \/\/ true, same as res4<\/code><\/pre>\n\n\n\n<p>By Yuuma<\/p>\n<div class='wp_social_bookmarking_light'>\n            <div class=\"wsbl_google_plus_one\"><g:plusone size=\"medium\" annotation=\"none\" href=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/8059\" ><\/g:plusone><\/div>\n            <div class=\"wsbl_hatena_button\"><a href=\"\/\/b.hatena.ne.jp\/entry\/https:\/\/www.gigas-jp.com\/appnews\/archives\/8059\" class=\"hatena-bookmark-button\" data-hatena-bookmark-title=\"Lodash Js Part 2(Chaining and has method)\" data-hatena-bookmark-layout=\"standard\" title=\"\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u306f\u3066\u306a\u30d6\u30c3\u30af\u30de\u30fc\u30af\u306b\u8ffd\u52a0\"> <img src=\"\/\/b.hatena.ne.jp\/images\/entry-button\/button-only@2x.png\" alt=\"\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u306f\u3066\u306a\u30d6\u30c3\u30af\u30de\u30fc\u30af\u306b\u8ffd\u52a0\" width=\"20\" height=\"20\" style=\"border: none;\" \/><\/a><script type=\"text\/javascript\" src=\"\/\/b.hatena.ne.jp\/js\/bookmark_button.js\" charset=\"utf-8\" async=\"async\"><\/script><\/div>\n            <div class=\"wsbl_twitter\"><a href=\"https:\/\/twitter.com\/share\" class=\"twitter-share-button\" data-url=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/8059\" data-text=\"Lodash Js Part 2(Chaining and has method)\" data-via=\"GIGASJAPAN_APPS\" data-lang=\"ja\">Tweet<\/a><\/div>\n            <div class=\"wsbl_facebook_like\"><div id=\"fb-root\"><\/div><fb:like href=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/8059\" layout=\"button_count\" action=\"like\" width=\"100\" share=\"false\" show_faces=\"false\" ><\/fb:like><\/div>\n            <div class=\"wsbl_facebook_send\"><div id=\"fb-root\"><\/div><fb:send href=\"https:\/\/www.gigas-jp.com\/appnews\/archives\/8059\" colorscheme=\"light\" ><\/fb:send><\/div>\n    <\/div>\n<br class='wp_social_bookmarking_light_clear' \/>\n","protected":false},"excerpt":{"rendered":"<p>Today I will talk about chaining functions and has method. Chaining Without Chaining With Chaining The chainin [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[100],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts\/8059"}],"collection":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/comments?post=8059"}],"version-history":[{"count":3,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts\/8059\/revisions"}],"predecessor-version":[{"id":8064,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/posts\/8059\/revisions\/8064"}],"wp:attachment":[{"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/media?parent=8059"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/categories?post=8059"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gigas-jp.com\/appnews\/wp-json\/wp\/v2\/tags?post=8059"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}