{"id":1469,"date":"2023-02-19T13:02:50","date_gmt":"2023-02-19T13:02:50","guid":{"rendered":"http:\/\/example.com\/?p=472"},"modified":"2023-02-19T13:02:50","modified_gmt":"2023-02-19T13:02:50","slug":"472-a-map-can-contain-duplicate-keys","status":"publish","type":"post","link":"https:\/\/w1.geleleger.nl\/rdswa-472-a-map-can-contain-duplicate-keys-fdpkm\/","title":{"rendered":"A Map Can Contain Duplicate Keys"},"content":{"rendered":"<div class=\"a1420ecab7e2234e1f4e9be5cee323bb\" data-index=\"1\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script type=\"text\/javascript\">\r\n\tatOptions = {\r\n\t\t'key' : '4a1f1119f949a4af74d56b8a3af8b867',\r\n\t\t'format' : 'iframe',\r\n\t\t'height' : 250,\r\n\t\t'width' : 300,\r\n\t\t'params' : {}\r\n\t};\r\n\tdocument.write('<scr' + 'ipt type=\"text\/javascript\" src=\"http' + (location.protocol === 'https:' ? 's' : '') + ':\/\/bleedingofficecontagion.com\/4a1f1119f949a4af74d56b8a3af8b867\/invoke.js\"><\/scr' + 'ipt>');\r\n<\/script>\n<\/div>\n\n<p><strong>A Map Can Contain Duplicate Keys<\/strong>. <strong>It is possible to retrieve directly a value using its key, so is not possible to have more values associated to the same key. The second element of the pair tells you whether the element has been inserted, or whether there was already an existing entry with the same key. However, I do not think that you need this. To get something similar, you can use a Map&lt;K, List&lt;V&gt;&gt;, which is a map containing a list of values for each key. From javadoc: A map cannot contain duplicate keys; each key can map to at most one value. Standard Maps Java has several implementations of the interface Map, each one with its own particularities.<\/strong><\/p>\n<p><figure> \t\t<img decoding=\"async\" src=\"http:\/\/www.mysqltutorial.org\/wp-content\/uploads\/2015\/12\/MySQL-Insert-on-duplicate-key-update-example.jpg\" alt=\"MySQL INSERT ON DUPLICATE KEY UPDATE\" style=\"width: 100%; padding: 5px; background-color: grey;\"><figcaption>MySQL INSERT ON DUPLICATE KEY UPDATE (Mattie Becker)<\/figcaption><\/figure>\n<p> \t \t<strong>A Map Can Contain Duplicate Keys<\/strong>. <strong>To merge values for duplicate keys you can check whether the key already exists before you put a new key-value pair into the map. This interface takes the place of the Dictionary class, which was a totally abstract class rather than an interface. It simply returns an iterator pointing to the existing element. std::map::insert() has a return value, which you should check. It is possible to retrieve directly a value using its key, so is not possible to have more values associated to the same key. Here is how my map and its data items are defined. public class ZTECase  public string OracleCaseNumber get;set;  Multimap is an associative container that stores elements in sorted key-value pairs as a tuple. However, I do not think that you need this.<\/strong> A Map Can Contain Duplicate Keys. <\/p>\n<h3>An object that maps keys to values.<\/h3>\n<p>How a map inserts: There cannot be a duplicate key in a Map.<\/p>\n<div style=\"display: grid;grid-template-columns: auto auto auto; background: #eee; \">\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/i0.wp.com\/pythonguides.com\/wp-content\/uploads\/2021\/08\/Python-dictionary-contains-duplicate-keys.png\"><img decoding=\"async\" src=\"https:\/\/i0.wp.com\/pythonguides.com\/wp-content\/uploads\/2021\/08\/Python-dictionary-contains-duplicate-keys.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse3.mm.bing.net\/th?id=OIP.xdZgGBC0jMDQELEMSHKZxQHaFz&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Python Dictionary Contains + Examples &#8211; Python Guides<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"http:\/\/autokeymasters.com\/wp-content\/uploads\/2016\/10\/Keys.png\"><img decoding=\"async\" src=\"http:\/\/autokeymasters.com\/wp-content\/uploads\/2016\/10\/Keys.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse4.mm.bing.net\/th?id=OIP.JEnDgqfPeS_cvF70NRSbCQHaEn&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Locksmith Service Can Get You Duplicate Keys in no Time &#8211; AKM<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/survivallife.com\/wp-content\/uploads\/2017\/02\/duplicate-keys-9.jpg\"><img decoding=\"async\" src=\"https:\/\/survivallife.com\/wp-content\/uploads\/2017\/02\/duplicate-keys-9.jpg\" onerror=\"this.onerror=null;this.src='https:\/\/tse4.mm.bing.net\/th?id=OIP.xhiyL4oSLOoKFrMpA3gP6QHaEK&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>4 Ways To Duplicate Keys By Hand &#8211; Total Survival<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div style=\"display: grid;grid-template-columns: auto auto auto; background: #eee; \">\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/blog.gunassociation.org\/wp-content\/uploads\/2017\/02\/289SL-4-Ways-To-Duplicate-Keys-By-Hand-476x1024.jpg\"><img decoding=\"async\" src=\"https:\/\/blog.gunassociation.org\/wp-content\/uploads\/2017\/02\/289SL-4-Ways-To-Duplicate-Keys-By-Hand-476x1024.jpg\" onerror=\"this.onerror=null;this.src='https:\/\/tse3.mm.bing.net\/th?id=OIP._CSaxECQ9EWqe77eDZCAfAHaP7&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>How To Duplicate Keys By Hand | Tips And Tricks To Make One Yourself<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/designtlc.com\/wp-content\/uploads\/2018\/09\/Image-2018-09-08-at-3.40.40-PM.png\"><img decoding=\"async\" src=\"https:\/\/designtlc.com\/wp-content\/uploads\/2018\/09\/Image-2018-09-08-at-3.40.40-PM.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse1.mm.bing.net\/th?id=OIP.3YYU38wqQQKxvEJYO6eDvQHaGW&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>33 Javascript Map With Duplicate Keys &#8211; Modern Javascript Blog<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/storage.googleapis.com\/programming-idioms-pictures\/idiom\/51\/map-contains-key.png\"><img decoding=\"async\" src=\"https:\/\/storage.googleapis.com\/programming-idioms-pictures\/idiom\/51\/map-contains-key.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse1.mm.bing.net\/th?id=OIP.gkC7fNpaud8rz2P2Hz8P1wAAAA&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Check if map contains key, in C++<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div style=\"display: grid;grid-template-columns: auto auto auto; background: #eee; \">\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/dm3z1jexb3zz4.cloudfront.net\/public\/images\/core\/Images\/App-Screenshots\/Remove-Duplicates-Step-2.jpg?mtime=20201027174126\"><img decoding=\"async\" src=\"https:\/\/dm3z1jexb3zz4.cloudfront.net\/public\/images\/core\/Images\/App-Screenshots\/Remove-Duplicates-Step-2.jpg?mtime=20201027174126\" onerror=\"this.onerror=null;this.src='https:\/\/tse3.mm.bing.net\/th?id=OIP.Ix1joRUBbJP-b2N9wcQLZgHaDi&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>How can I remove duplicate accounts? &#8211; Badger Maps<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/1.bp.blogspot.com\/-Aa8nLjpE8ns\/XxvqiFBp-SI\/AAAAAAAAC20\/8_xVvByt0asv4RiXPWtMD7pKAeyPU3sewCLcBGAsYHQ\/s1874\/Java%2B8%2B-%2BConvert%2BList%2Bto%2BMap%2B%2528Handling%2BDuplicate%2BKeys%2529.png\"><img decoding=\"async\" src=\"https:\/\/1.bp.blogspot.com\/-Aa8nLjpE8ns\/XxvqiFBp-SI\/AAAAAAAAC20\/8_xVvByt0asv4RiXPWtMD7pKAeyPU3sewCLcBGAsYHQ\/s1874\/Java%2B8%2B-%2BConvert%2BList%2Bto%2BMap%2B%2528Handling%2BDuplicate%2BKeys%2529.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse3.mm.bing.net\/th?id=OIP.KU9c1RLpkMbjIXiQEbvFzQHaD5&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Java 8 &#8211; Convert List to Map (Handling Duplicate Keys) | JavaProgramTo.com<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/media.cheggcdn.com\/media\/93d\/93dfd5a0-c6b3-4a31-9852-7ed66196a55e\/phpCtWt2R.png\"><img decoding=\"async\" src=\"https:\/\/media.cheggcdn.com\/media\/93d\/93dfd5a0-c6b3-4a31-9852-7ed66196a55e\/phpCtWt2R.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse1.mm.bing.net\/th?id=OIP.Yhjh9I9zD4olP48oBsnrYQHaHb&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Solved: Introduction A Map is an object that maps keys to<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<div style=\"display: grid;grid-template-columns: auto auto auto; background: #eee; \">\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/i.stack.imgur.com\/xJ4LR.png\"><img decoding=\"async\" src=\"https:\/\/i.stack.imgur.com\/xJ4LR.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse1.mm.bing.net\/th?id=OIP.XzcR9ZBLct2iNdEHUxvbwQHaDo&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Map Java With Duplicate Keys &#8211; Maps of the World<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/blogs.sap.com\/wp-content\/uploads\/2017\/07\/5-6.png\"><img decoding=\"async\" src=\"https:\/\/blogs.sap.com\/wp-content\/uploads\/2017\/07\/5-6.png\" onerror=\"this.onerror=null;this.src='https:\/\/tse3.mm.bing.net\/th?id=OIP.Kbxx5RrBYDY1lqzNdQecrAHaCf&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Table Comparison: Input Contains Duplicate Keys | SAP Blogs<\/p>\n<\/p><\/div>\n<div style=\"padding: 1em;\"> \t\t        <a href=\"https:\/\/1.bp.blogspot.com\/-2FLYvZnnS9A\/XqbWC3gdoXI\/AAAAAAAAeno\/aH0dw1TSnDkl97NtL1pQo63NSYwZOwLxwCLcBGAsYHQ\/w1200-h630-p-k-no-nu\/How+to+check+if+a+key+exists+in+HashMap+in+Java.jpg\"><img decoding=\"async\" src=\"https:\/\/1.bp.blogspot.com\/-2FLYvZnnS9A\/XqbWC3gdoXI\/AAAAAAAAeno\/aH0dw1TSnDkl97NtL1pQo63NSYwZOwLxwCLcBGAsYHQ\/w1200-h630-p-k-no-nu\/How+to+check+if+a+key+exists+in+HashMap+in+Java.jpg\" onerror=\"this.onerror=null;this.src='https:\/\/tse4.mm.bing.net\/th?id=OIP.1v6a0u4AC3KAlkkn9hoRXQHaD5&amp;pid=Api';\" style=\"width:100%;margin-top: 8px;vertical-align: middle;\"><\/a> \t\t        <\/p>\n<p>Java HashMap ContainsKey and ContainsValue Example<\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><strong>A Map Can Contain Duplicate Keys<\/strong>. <strong>It simply returns an iterator pointing to the existing element. std::map::insert() has a return value, which you should check. Experts are tested by Chegg as specialists in their subject area. It is possible to retrieve directly a value using its key, so is not possible to have more values associated to the same key. An HashMap is a data structure where is possible to save couples of key values. It is quite similar to the map, but the difference is that it can also contain duplicate keys that are not unique. The best you can do is have something like a list in the values. i.e.<\/p>\n<p><\/strong> A Map Can Contain Duplicate Keys.<\/p>\n<div class=\"a1420ecab7e2234e1f4e9be5cee323bb\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script type=\"text\/javascript\">\r\n\tatOptions = {\r\n\t\t'key' : '4a1f1119f949a4af74d56b8a3af8b867',\r\n\t\t'format' : 'iframe',\r\n\t\t'height' : 250,\r\n\t\t'width' : 300,\r\n\t\t'params' : {}\r\n\t};\r\n\tdocument.write('<scr' + 'ipt type=\"text\/javascript\" src=\"http' + (location.protocol === 'https:' ? 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It is possible to retrieve directly a value using its key, so is not [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/posts\/1469"}],"collection":[{"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/comments?post=1469"}],"version-history":[{"count":0,"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/posts\/1469\/revisions"}],"wp:attachment":[{"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/media?parent=1469"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/categories?post=1469"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/w1.geleleger.nl\/wp-json\/wp\/v2\/tags?post=1469"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}