{"id":2418,"date":"2023-06-25T20:53:14","date_gmt":"2023-06-25T13:53:14","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=2418"},"modified":"2023-06-25T20:53:59","modified_gmt":"2023-06-25T13:53:59","slug":"linq-maxby","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-linq\/linq-maxby\/","title":{"rendered":"LINQ MaxBy"},"content":{"rendered":"\n<p><strong>Summary<\/strong>: in this tutorial, you will learn how to use the LINQ <code>MaxBy()<\/code> method to return the element with the maximum value in a sequence.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Introduction to the LINQ MaxBy() method<\/h2>\n\n\n\n<p>The <code>MaxBy()<\/code> method returns the maximum value in a sequence based on a key selector function:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\">TSource? MaxBy&lt;TSource,TKey&gt; (\n    <span class=\"hljs-keyword\">this<\/span> Enumerable&lt;TSource&gt; source, \n    Func&lt;TSource,TKey&gt; keySelector\n);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>In this syntax;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>TSource<\/code> is the type of element in the source sequence.<\/li>\n\n\n\n<li><code>TKey<\/code> is a type of key used to compare elements.<\/li>\n\n\n\n<li><code>source<\/code> is an input sequence of elements with <code><a href=\"https:\/\/csharptutorial.net\/csharp-linq\/csharp-ienumerable\/\">IEnumerable&lt;TSource><\/a><\/code> type.<\/li>\n\n\n\n<li><code>keySelector<\/code> is a function that extracts the key for each element.<\/li>\n<\/ul>\n\n\n\n<p>The LINQ <code>MaxBy()<\/code> returns the value with the maximum key in the sequence.<\/p>\n\n\n\n<p>Note that the <code><a href=\"https:\/\/csharptutorial.net\/csharp-linq\/linq-max\/\">Max()<\/a><\/code> method returns the maximum value of elements by a key while the <code>MaxBy()<\/code> method returns the element with the maximum value by the key.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">LINQ MaxBy() method examples<\/h2>\n\n\n\n<p>Suppose you have a <code>Product<\/code> class that has three properties <code>Name<\/code>, <code>Cost<\/code>, and <code>Price<\/code>:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-2\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\"><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">class<\/span> <span class=\"hljs-title\">Product<\/span>\n{\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">string<\/span> Name\n    {\n        <span class=\"hljs-keyword\">get<\/span>; <span class=\"hljs-keyword\">set<\/span>;\n    }\n\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">decimal<\/span> Price\n    {\n        <span class=\"hljs-keyword\">get<\/span>; <span class=\"hljs-keyword\">set<\/span>;\n    }\n\n    <span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">decimal<\/span> Cost\n    {\n        <span class=\"hljs-keyword\">get<\/span>; <span class=\"hljs-keyword\">set<\/span>;\n    }\n\n    <span class=\"hljs-function\"><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-title\">Product<\/span>(<span class=\"hljs-params\"><span class=\"hljs-keyword\">string<\/span> name, <span class=\"hljs-keyword\">decimal<\/span> cost, <span class=\"hljs-keyword\">decimal<\/span> price<\/span>)<\/span>\n    {\n        Name = name;\n        Cost = cost;\n        Price = price;\n    }\n\n    <span class=\"hljs-function\"><span class=\"hljs-keyword\">public<\/span> <span class=\"hljs-keyword\">override<\/span> <span class=\"hljs-keyword\">string<\/span> <span class=\"hljs-title\">ToString<\/span>(<span class=\"hljs-params\"><\/span>)<\/span> =&gt; <span class=\"hljs-string\">$\"<span class=\"hljs-subst\">{Name}<\/span>, Cost:<span class=\"hljs-subst\">{Cost}<\/span>, Price:<span class=\"hljs-subst\">{Price}<\/span>\"<\/span>;\n}<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-2\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>The following program uses the <code>MaxBy()<\/code> method to find the product that has the highest price:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-3\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\"><span class=\"hljs-keyword\">using<\/span> <span class=\"hljs-keyword\">static<\/span> System.Console;\n\n<span class=\"hljs-keyword\">var<\/span> products = <span class=\"hljs-keyword\">new<\/span> List&lt;Product&gt;() {\n    <span class=\"hljs-keyword\">new<\/span> Product(name:<span class=\"hljs-string\">\"A\"<\/span>,cost:<span class=\"hljs-number\">100<\/span>,price:<span class=\"hljs-number\">160<\/span>),\n    <span class=\"hljs-keyword\">new<\/span> Product(name:<span class=\"hljs-string\">\"B\"<\/span>,cost:<span class=\"hljs-number\">95<\/span>,price:<span class=\"hljs-number\">130<\/span>),\n    <span class=\"hljs-keyword\">new<\/span> Product(name:<span class=\"hljs-string\">\"C\"<\/span>,cost:<span class=\"hljs-number\">140<\/span>,price:<span class=\"hljs-number\">150<\/span>),\n};\n\n<span class=\"hljs-keyword\">var<\/span> product = products.MaxBy(p =&gt; p.Price);\n\nWriteLine(product);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-3\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-4\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\">A, Cost:<span class=\"hljs-number\">100<\/span>, Price:<span class=\"hljs-number\">160<\/span><\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-4\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>It returns product A with a price of 160.<\/p>\n\n\n\n<p>To find the product with the highest cost, you change the key selector function to select the <code>Cost<\/code>  property instead of Price property as follows:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-5\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\"><span class=\"hljs-keyword\">using<\/span> <span class=\"hljs-keyword\">static<\/span> System.Console;\n\n<span class=\"hljs-keyword\">var<\/span> products = <span class=\"hljs-keyword\">new<\/span> List&lt;Product&gt;() {\n    <span class=\"hljs-keyword\">new<\/span> Product(name:<span class=\"hljs-string\">\"A\"<\/span>,cost:<span class=\"hljs-number\">100<\/span>,price:<span class=\"hljs-number\">160<\/span>),\n    <span class=\"hljs-keyword\">new<\/span> Product(name:<span class=\"hljs-string\">\"B\"<\/span>,cost:<span class=\"hljs-number\">95<\/span>,price:<span class=\"hljs-number\">130<\/span>),\n    <span class=\"hljs-keyword\">new<\/span> Product(name:<span class=\"hljs-string\">\"C\"<\/span>,cost:<span class=\"hljs-number\">140<\/span>,price:<span class=\"hljs-number\">150<\/span>),\n};\n\n<span class=\"hljs-keyword\">var<\/span> product = products.MaxBy(p =&gt; p.Cost);\n\nWriteLine(product);<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-5\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<p>Output:<\/p>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-6\" data-shcb-language-name=\"C#\" data-shcb-language-slug=\"cs\"><span><code class=\"hljs language-cs\">C, Cost:<span class=\"hljs-number\">140<\/span>, Price:<span class=\"hljs-number\">150<\/span><\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-6\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">C#<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">cs<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<h2 class=\"wp-block-heading\">Summary<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use the LINQ <code>MaxBy()<\/code> method to return the element with the maximum value in a sequence.<\/li>\n<\/ul>\n<div class=\"helpful-block-content\" data-title=\"\">\n\t<header>\n\t\t<div class=\"wth-question\">Was this tutorial helpful ?<\/div>\n\t\t<div class=\"wth-thumbs\">\n\t\t\t<button\n\t\t\t\tdata-post=\"2418\"\n\t\t\t\tdata-post-url=\"https:\/\/www.csharptutorial.net\/csharp-linq\/linq-maxby\/\"\n\t\t\t\tdata-post-title=\"LINQ MaxBy\"\n\t\t\t\tdata-response=\"1\"\n\t\t\t\tclass=\"wth-btn-rounded wth-yes-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t\tclass=\"feather feather-thumbs-up block w-full h-full\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M14 9V5a3 3 0 0 0-3-3l-4 9v11h11.28a2 2 0 0 0 2-1.7l1.38-9a2 2 0 0 0-2-2.3zM7 22H4a2 2 0 0 1-2-2v-7a2 2 0 0 1 2-2h3\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> Yes <\/span>\n\t\t\t<\/button>\n\n\t\t\t<button\n\t\t\t\tdata-response=\"0\"\n\t\t\t\tdata-post=\"2418\"\n\t\t\t\tdata-post-url=\"https:\/\/www.csharptutorial.net\/csharp-linq\/linq-maxby\/\"\n\t\t\t\tdata-post-title=\"LINQ MaxBy\"\n\t\t\t\tclass=\"wth-btn-rounded wth-no-btn\"\n\t\t\t>\n\t\t\t\t<svg\n\t\t\t\t\txmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n\t\t\t\t\tviewBox=\"0 0 24 24\"\n\t\t\t\t\tfill=\"none\"\n\t\t\t\t\tstroke=\"currentColor\"\n\t\t\t\t\tstroke-width=\"2\"\n\t\t\t\t\tstroke-linecap=\"round\"\n\t\t\t\t\tstroke-linejoin=\"round\"\n\t\t\t\t>\n\t\t\t\t\t<path\n\t\t\t\t\t\td=\"M10 15v4a3 3 0 0 0 3 3l4-9V2H5.72a2 2 0 0 0-2 1.7l-1.38 9a2 2 0 0 0 2 2.3zm7-13h2.67A2.31 2.31 0 0 1 22 4v7a2.31 2.31 0 0 1-2.33 2H17\"\n\t\t\t\t\t><\/path>\n\t\t\t\t<\/svg>\n\t\t\t\t<span class=\"sr-only\"> No <\/span>\n\t\t\t<\/button>\n\t\t<\/div>\n\t<\/header>\n\n\t<div class=\"wth-form hidden\">\n\t\t<div class=\"wth-form-wrapper\">\n\t\t\t<div class=\"wth-title\"><\/div>\n\t\t\t\n\t\t\t<textarea class=\"wth-message\"><\/textarea>\n\n\t\t\t<button class=\"btn btn-primary wth-btn-submit\">Send<\/button>\n\t\t\t<button class=\"btn wth-btn-cancel\">Cancel<\/button>\n\t\t\n\t\t<\/div>\n\t<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>In this tutorial, you will learn how to use the LINQ MaxBy() method to return the element with the maximum value in a sequence.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":919,"menu_order":38,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-2418","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/2418","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/comments?post=2418"}],"version-history":[{"count":3,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/2418\/revisions"}],"predecessor-version":[{"id":2425,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/2418\/revisions\/2425"}],"up":[{"embeddable":true,"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/pages\/919"}],"wp:attachment":[{"href":"https:\/\/www.csharptutorial.net\/wp-json\/wp\/v2\/media?parent=2418"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}