{"id":2216,"date":"2020-06-09T14:33:46","date_gmt":"2020-06-09T09:03:46","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=2216"},"modified":"2020-06-09T14:33:58","modified_gmt":"2020-06-09T09:03:58","slug":"check-key-exists-map-golang","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/check-key-exists-map-golang\/","title":{"rendered":"An efficient way to check if a key exists in a Map in Go (Golang)"},"content":{"rendered":"\n<p class=\"has-medium-font-size\">Below is the format to check if a key exist in the map<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">val, ok := mapName[key]<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">There are two cases<\/p>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>If the key exists <strong>val <\/strong>variable be the value of the key in the map and <strong>ok <\/strong>variable will be true<\/li><\/ul>\n\n\n\n<ul class=\"has-medium-font-size wp-block-list\"><li>If the key doesn&#8217;t exist <strong>val<\/strong> variable will be default zero value of value type and <strong>ok <\/strong>variable will be false<\/li><\/ul>\n\n\n\n<p class=\"has-medium-font-size\">Let&#8217;s see an example<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">package main\n\nimport \"fmt\"\n\nfunc main() {\n    \/\/Declare\n    employeeSalary := make(map[string]int)\n\n    \/\/Adding a key value\n    employeeSalary[\"Tom\"] = 2000\n    fmt.Println(\"Key exists case\")\n    val, ok := employeeSalary[\"Tom\"]\n    fmt.Printf(\"Val: %d, ok: %t\\n\", val, ok)\n    fmt.Println(\"Key doesn't exists case\")\n\n    val, ok = employeeSalary[\"Sam\"]\n    fmt.Printf(\"Val: %d, ok: %t\\n\", val, ok)\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Output<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">Key exists case\nVal: 2000, ok: true\nKey doesn't exists case\nVal: 0, ok: false<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">In above program when key exists then <strong>val<\/strong> variable is set to the actual value which is 2000 here\u00a0 and <strong>ok<\/strong> variable is true. When key doesn&#8217;t exist the <strong>val<\/strong> variable is set to 0 which is default zero value of int and <strong>ok<\/strong> variable is false. This <strong>ok<\/strong> variable is the best way to check if the key exists in a map or not<\/p>\n\n\n\n<p class=\"has-medium-font-size\">In case we only want to check if a key is present and val is not needed, then blank identifier i.e &#8220;_&#8221; can be used in place of val.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">_, ok = employeeSalary[\"Sam\"]<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Below is the format to check if a key exist in the map There are two cases If the key exists val variable be the value of the key in the map&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[1],"tags":[297,3,4],"class_list":["post-2216","post","type-post","status-publish","format-standard","hentry","category-tech","tag-exists","tag-go","tag-golang"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - 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