{"id":12009,"date":"2022-02-13T17:55:46","date_gmt":"2022-02-13T08:55:46","guid":{"rendered":"http:\/\/www.gisdeveloper.co.kr\/?p=12009"},"modified":"2022-02-13T18:04:45","modified_gmt":"2022-02-13T09:04:45","slug":"%ec%9e%90%eb%b0%94%ec%8a%a4%ed%81%ac%eb%a6%bd%ed%8a%b8%ec%9d%98-optional-channing-nullish-coalescing-operator-%eb%ac%b8%eb%b2%95","status":"publish","type":"post","link":"http:\/\/www.gisdeveloper.co.kr\/?p=12009","title":{"rendered":"\uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8\uc758 Optional Channing, Nullish Coalescing Operator \ubb38\ubc95"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/www.gisdeveloper.co.kr\/wp-content\/uploads\/2022\/02\/ecmascript6.png\" alt=\"\" width=\"800\" height=\"429\" class=\"aligncenter size-full wp-image-12013\" \/><\/p>\n<p>\uc6a9\uc5b4 \uc790\uccb4\uac00 \uc774\ub9ac \uc5b4\ub824\uc6b0\ub2c8 \uac1c\ub150\uc740 \uac04\ub2e8\ud558\uace0 \ub9e4\uc6b0 \uc88b\uc740 \uae30\ub2a5\uc784\uc5d0\ub3c4 \uc190\uc5d0 \uc798.. \uc548\ubd99\uc2b5\ub2c8\ub2e4.<\/p>\n<p>Optional Channing\uc740 ?. \ud0a4\uc6cc\ub4dc\ub85c \uc0ac\uc6a9\ub418\uba70 \uac1d\uccb4\uc5d0 \uc5b4\ub5a4 \uc18d\uc131\uc774 \uc788\ub2e4\uba74 \uadf8 \uc18d\uc131\uc744 \ubc18\ud658\ud558\uace0 \uc5c6\ub2e4\uba74 undefined\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. \uc989 if \ubb38\uc73c\ub85c \ud574\ub2f9 \uc18d\uc131\uc744 \uac80\uc0ac\ud560 \ud544\uc694\uac00 \uc5c6\uc2b5\ub2c8\ub2e4. \uc774 Optional Channing\uc758 \uc608\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"js\">\r\nconst person = { name: \"Dip2K\", company: { name: \"GEOSERVICE\", address: \"Korea, Seoul\" }};\r\nconsole.log(person.company?.name); \/\/ GEOSERVICE\r\nconsole.log(person.skill?.language); \/\/ undefined\r\n<\/pre>\n<p>Optional Channing\uc740 \ub9e4\uc11c\ub4dc \ud638\ucd9c\uc5d0 \ub300\ud574\uc11c\ub3c4 \uc0ac\uc6a9\ud560 \uc218 \uc788\ub294\ub370\uc694. \uac1d\uccb4\uc5d0 \uc5b4\ub5a4 \ub9e4\uc11c\ub4dc\uac00 \uc874\uc7ac\ud560 \ub54c \uadf8 \ub9e4\uc11c\ub4dc\ub97c \ud638\ucd9c\ud574\uc57c \ud55c\ub2e4\uba74 if \ubb38\uc73c\ub85c \ub9e4\uc11c\ub4dc \uc874\uc7ac \uc5ec\ubd80\ub97c \uac80\uc0ac\ud560 \ud544\uc694 \uc5c6\uc774 \ub2e4\uc74c\ucc98\ub7fc \ud558\uba74 \ub429\ub2c8\ub2e4.<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"js\">\r\nconst obj = {\r\n    getName() {\r\n        console.log(\"Dip2K\");\r\n    }\r\n};\r\n\r\nconsole.log(obj.getName?.()); \/\/ Dip2K\r\nconsole.log(obj.getAge?.()); \/\/ undefined\r\n<\/pre>\n<p>\uacb0\uad6d ?.\uc740 \ubc14\ub85c \uc9c1\uc804\uc5d0 \ubd99\uc740 \ub140\uc11d\uc774 \uc874\uc7ac\ud558\uba74 \uadf8 \ub140\uc11d\uc744 \ubc18\ud658\ud558\uace0 \uc874\uc7ac\ud558\uc9c0 \uc54a\ub294 \ub140\uc11d\uc774\uba74 \uc989\uac01 undefined\ub97c \ubc18\ud658\ud558\uace0 \ub05d\ub0a9\ub2c8\ub2e4.<\/p>\n<p>\ub2e4\uc74c\uc740 Nullish Coalescing Operator\uc785\ub2c8\ub2e4. ?? \ud0a4\uc6cc\ub4dc\ub85c \uc0ac\uc6a9\ub418\uba70 ?? \ud0a4\uc6cc\ub4dc\ub97c \uc911\uc2ec\uc73c\ub85c \uc67c\ucabd\uac12\uc774 \uba85\ud655\ud788 null \ub610\ub294 undefiend \uc77c\ub54c \uc624\ub978\ucabd\uc758 \uac12\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. \uba85\ud655\ud788 null \ub610\ub294 undefined\uc774\ub77c\ub294 \uc758\ubbf8\ub294 0\uc774\ub098 \ube48\ubb38\uc790\uc5f4 \ub4f1\uc740 null \ub610\ub294 undefiend\ub85c \ud574\uc11d\ub418\uc9c0 \uc54a\uc2b5\ub2c8\ub2e4. \uc608\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4.<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"js\">\r\nlet name = \"Dip2K\";\r\nconsole.log(name ?? \"Jackass\"); \/\/ Dip2K \r\n\r\nlet age = 0;\r\nconsole.log(age ?? 10); \/\/ 0\r\n\r\nlet last_name = undefined;\r\nconsole.log(last_name ?? \"Jackson\"); \/\/ Jackson\r\n<\/pre>\n<p>\uacb0\uad6d \uc774 \uc774\ub984\ub9cc \uac70\ucc3d\ud55c \ub140\uc11d\uc740 \uac12\uc774 \uc788\uc74c? \uc5c6\uc74c \ub9d0\uace0(undefined)\uc785\ub2c8\ub2e4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\uc6a9\uc5b4 \uc790\uccb4\uac00 \uc774\ub9ac \uc5b4\ub824\uc6b0\ub2c8 \uac1c\ub150\uc740 \uac04\ub2e8\ud558\uace0 \ub9e4\uc6b0 \uc88b\uc740 \uae30\ub2a5\uc784\uc5d0\ub3c4 \uc190\uc5d0 \uc798.. \uc548\ubd99\uc2b5\ub2c8\ub2e4. Optional Channing\uc740 ?. \ud0a4\uc6cc\ub4dc\ub85c \uc0ac\uc6a9\ub418\uba70 \uac1d\uccb4\uc5d0 \uc5b4\ub5a4 \uc18d\uc131\uc774 \uc788\ub2e4\uba74 \uadf8 \uc18d\uc131\uc744 \ubc18\ud658\ud558\uace0 \uc5c6\ub2e4\uba74 undefined\uc744 \ubc18\ud658\ud569\ub2c8\ub2e4. \uc989 if \ubb38\uc73c\ub85c \ud574\ub2f9 \uc18d\uc131\uc744 \uac80\uc0ac\ud560 \ud544\uc694\uac00 \uc5c6\uc2b5\ub2c8\ub2e4. \uc774 Optional Channing\uc758 \uc608\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4. const person = { name: &#8220;Dip2K&#8221;, company: { name: &#8220;GEOSERVICE&#8221;, address: &#8220;Korea, Seoul&#8221; }}; &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/www.gisdeveloper.co.kr\/?p=12009\" class=\"more-link\">\ub354 \ubcf4\uae30<span class=\"screen-reader-text\"> &#8220;\uc790\ubc14\uc2a4\ud06c\ub9bd\ud2b8\uc758 Optional Channing, Nullish Coalescing Operator \ubb38\ubc95&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-12009","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/12009","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12009"}],"version-history":[{"count":5,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/12009\/revisions"}],"predecessor-version":[{"id":12012,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/12009\/revisions\/12012"}],"wp:attachment":[{"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12009"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12009"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.gisdeveloper.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12009"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}