{"id":22836,"date":"2024-03-16T00:14:29","date_gmt":"2024-03-16T00:14:29","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/"},"modified":"2024-03-21T23:49:46","modified_gmt":"2024-03-21T23:49:46","slug":"how-do-you-iterate-through-a-hashmap","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/","title":{"rendered":"How do you iterate through a hashmap?"},"content":{"rendered":"<p>There are several ways to traverse a HashMap.<\/p>\n<ol>\n<li>Traverse using an Iterator:<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code>HashMap&lt;String, Integer&gt; hashMap = <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">HashMap<\/span>&lt;&gt;();\r\n<span class=\"hljs-comment\">\/\/ \u6dfb\u52a0\u5143\u7d20\u5230HashMap<\/span>\r\nhashMap.put(<span class=\"hljs-string\">\"A\"<\/span>, <span class=\"hljs-number\">1<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"B\"<\/span>, <span class=\"hljs-number\">2<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"C\"<\/span>, <span class=\"hljs-number\">3<\/span>);\r\n\r\nIterator&lt;Map.Entry&lt;String, Integer&gt;&gt; iterator = hashMap.entrySet().iterator();\r\n<span class=\"hljs-keyword\">while<\/span> (iterator.hasNext()) {\r\n    Map.Entry&lt;String, Integer&gt; entry = iterator.next();\r\n    <span class=\"hljs-type\">String<\/span> <span class=\"hljs-variable\">key<\/span> <span class=\"hljs-operator\">=<\/span> entry.getKey();\r\n    <span class=\"hljs-type\">Integer<\/span> <span class=\"hljs-variable\">value<\/span> <span class=\"hljs-operator\">=<\/span> entry.getValue();\r\n    <span class=\"hljs-comment\">\/\/ \u5728\u8fd9\u91cc\u5904\u7406key\u548cvalue<\/span>\r\n}\r\n<\/code><\/pre>\n<ol>\n<li>Traverse using a For-Each loop:<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code>HashMap&lt;String, Integer&gt; hashMap = <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">HashMap<\/span>&lt;&gt;();\r\n<span class=\"hljs-comment\">\/\/ \u6dfb\u52a0\u5143\u7d20\u5230HashMap<\/span>\r\nhashMap.put(<span class=\"hljs-string\">\"A\"<\/span>, <span class=\"hljs-number\">1<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"B\"<\/span>, <span class=\"hljs-number\">2<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"C\"<\/span>, <span class=\"hljs-number\">3<\/span>);\r\n\r\n<span class=\"hljs-keyword\">for<\/span> (Map.Entry&lt;String, Integer&gt; entry : hashMap.entrySet()) {\r\n    <span class=\"hljs-type\">String<\/span> <span class=\"hljs-variable\">key<\/span> <span class=\"hljs-operator\">=<\/span> entry.getKey();\r\n    <span class=\"hljs-type\">Integer<\/span> <span class=\"hljs-variable\">value<\/span> <span class=\"hljs-operator\">=<\/span> entry.getValue();\r\n    <span class=\"hljs-comment\">\/\/ \u5728\u8fd9\u91cc\u5904\u7406key\u548cvalue<\/span>\r\n}\r\n<\/code><\/pre>\n<ol>\n<li>Iterate through all keys.<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code>HashMap&lt;String, Integer&gt; hashMap = <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">HashMap<\/span>&lt;&gt;();\r\n<span class=\"hljs-comment\">\/\/ \u6dfb\u52a0\u5143\u7d20\u5230HashMap<\/span>\r\nhashMap.put(<span class=\"hljs-string\">\"A\"<\/span>, <span class=\"hljs-number\">1<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"B\"<\/span>, <span class=\"hljs-number\">2<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"C\"<\/span>, <span class=\"hljs-number\">3<\/span>);\r\n\r\n<span class=\"hljs-keyword\">for<\/span> (String key : hashMap.keySet()) {\r\n    <span class=\"hljs-type\">Integer<\/span> <span class=\"hljs-variable\">value<\/span> <span class=\"hljs-operator\">=<\/span> hashMap.get(key);\r\n    <span class=\"hljs-comment\">\/\/ \u5728\u8fd9\u91cc\u5904\u7406key\u548cvalue<\/span>\r\n}\r\n<\/code><\/pre>\n<ol>\n<li>Iterate through all values.<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code>HashMap&lt;String, Integer&gt; hashMap = <span class=\"hljs-keyword\">new<\/span> <span class=\"hljs-title class_\">HashMap<\/span>&lt;&gt;();\r\n<span class=\"hljs-comment\">\/\/ \u6dfb\u52a0\u5143\u7d20\u5230HashMap<\/span>\r\nhashMap.put(<span class=\"hljs-string\">\"A\"<\/span>, <span class=\"hljs-number\">1<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"B\"<\/span>, <span class=\"hljs-number\">2<\/span>);\r\nhashMap.put(<span class=\"hljs-string\">\"C\"<\/span>, <span class=\"hljs-number\">3<\/span>);\r\n\r\n<span class=\"hljs-keyword\">for<\/span> (Integer value : hashMap.values()) {\r\n    <span class=\"hljs-comment\">\/\/ \u5728\u8fd9\u91cc\u5904\u7406value<\/span>\r\n}\r\n<\/code><\/pre>\n<p>Please choose the appropriate traversal method based on specific needs.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>There are several ways to traverse a HashMap. Traverse using an Iterator: HashMap&lt;String, Integer&gt; hashMap = new HashMap&lt;&gt;(); \/\/ \u6dfb\u52a0\u5143\u7d20\u5230HashMap hashMap.put(&#8220;A&#8221;, 1); hashMap.put(&#8220;B&#8221;, 2); hashMap.put(&#8220;C&#8221;, 3); Iterator&lt;Map.Entry&lt;String, Integer&gt;&gt; iterator = hashMap.entrySet().iterator(); while (iterator.hasNext()) { Map.Entry&lt;String, Integer&gt; entry = iterator.next(); String key = entry.getKey(); Integer value = entry.getValue(); \/\/ \u5728\u8fd9\u91cc\u5904\u7406key\u548cvalue } Traverse using a For-Each loop: [&hellip;]<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-22836","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>How do you iterate through a hashmap? - Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How do you iterate through a hashmap?\" \/>\n<meta property=\"og:description\" content=\"There are several ways to traverse a HashMap. Traverse using an Iterator: HashMap&lt;String, Integer&gt; hashMap = new HashMap&lt;&gt;(); \/\/ \u6dfb\u52a0\u5143\u7d20\u5230HashMap hashMap.put(&quot;A&quot;, 1); hashMap.put(&quot;B&quot;, 2); hashMap.put(&quot;C&quot;, 3); Iterator&lt;Map.Entry&lt;String, Integer&gt;&gt; iterator = hashMap.entrySet().iterator(); while (iterator.hasNext()) { Map.Entry&lt;String, Integer&gt; entry = iterator.next(); String key = entry.getKey(); Integer value = entry.getValue(); \/\/ \u5728\u8fd9\u91cc\u5904\u7406key\u548cvalue } Traverse using a For-Each loop: [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - Silicon Cloud\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/SiliCloudGlobal\/\" \/>\n<meta property=\"article:published_time\" content=\"2024-03-16T00:14:29+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-03-21T23:49:46+00:00\" \/>\n<meta name=\"author\" content=\"William Carter\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@SiliCloudGlobal\" \/>\n<meta name=\"twitter:site\" content=\"@SiliCloudGlobal\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"William Carter\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/\"},\"author\":{\"name\":\"William Carter\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/f697031891aacefc4b681d139781d3c0\"},\"headline\":\"How do you iterate through a hashmap?\",\"datePublished\":\"2024-03-16T00:14:29+00:00\",\"dateModified\":\"2024-03-21T23:49:46+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/\"},\"wordCount\":42,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/#organization\"},\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/\",\"url\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-iterate-through-a-hashmap\/\",\"name\":\"How do you iterate through a hashmap? 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