{"id":516,"date":"2025-03-21T09:46:53","date_gmt":"2025-03-21T00:46:53","guid":{"rendered":"https:\/\/www.kd2.jp\/memo3\/?p=516"},"modified":"2025-03-21T09:47:20","modified_gmt":"2025-03-21T00:47:20","slug":"list%e3%81%a8intstream","status":"publish","type":"post","link":"https:\/\/www.kd2.jp\/memo3\/?p=516","title":{"rendered":"Java List\u3068IntStream"},"content":{"rendered":"<div class=\"wp-block-codemirror-blocks code-block \">\n<pre class=\"CodeMirror\" data-setting=\"{&quot;mode&quot;:&quot;clike&quot;,&quot;mime&quot;:&quot;text\/x-java&quot;,&quot;theme&quot;:&quot;eclipse&quot;,&quot;lineNumbers&quot;:true,&quot;lineWrapping&quot;:false,&quot;styleActiveLine&quot;:false,&quot;readOnly&quot;:true,&quot;align&quot;:&quot;&quot;}\">import java.util.ArrayList;\r\nimport java.util.List;\r\n\r\npublic class IntStreamTest1 {\r\n\r\n    public static void main(String[] args) {\r\n\r\n        List&lt;Person&gt; people = new ArrayList&lt;&gt;();\r\n        people.add(new Person(\"Alice\", 30));\r\n        people.add(new Person(\"Bob\", 19));\r\n        people.add(new Person(\"Ronald\", 40));\r\n        people.add(new Person(\"Jimi\", 27));\r\n        people.add(new Person(\"Suzan\", 60));\r\n        people.add(new Person(\"Jeff\", 80));\r\n        people.add(new Person(\"Maria\", 52));\r\n\r\n        \/\/ min\r\n        int min = people.stream().mapToInt(p -&gt; p.getAge()).min().orElse(0);\r\n        System.out.println(min);\r\n        \/\/ 19\r\n\r\n        \/\/ max\r\n        int max = people.stream().mapToInt(p -&gt; p.getAge()).max().orElse(0);\r\n        System.out.println(max);\r\n        \/\/ 80\r\n\r\n        \/\/ sum\r\n        int sum = people.stream().mapToInt(p -&gt; p.getAge()).sum();\r\n        System.out.println(sum);\r\n        \/\/ 308\r\n\r\n        \/\/ average\r\n        double ave = people.stream().mapToInt(p -&gt; p.getAge()).average().orElse(0.0);\r\n        System.out.println(ave);\r\n        \/\/ 44.0\r\n    }\r\n}\r\n\r\nclass Person {\r\n\r\n    private String name;\r\n    private Integer age;\r\n\r\n    public Person(String name, Integer age) {\r\n        this.name = name;\r\n        this.age = age;\r\n    }\r\n\r\n    public Integer getAge() {\r\n        return age;\r\n    }\r\n\r\n    public String getName() {\r\n        return name;\r\n    }\r\n\r\n    public String toString() {\r\n        return \"name:\" + name + \" age:\" + age;\r\n    }\r\n}<\/pre>\n<\/div>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>import java.util.ArrayList; import java.util.List; public class IntStreamTest1 { public static void main(Strin&hellip; <a class=\"more-link\" href=\"https:\/\/www.kd2.jp\/memo3\/?p=516\">\u7d9a\u304d\u3092\u8aad\u3080 <span class=\"screen-reader-text\">Java List\u3068IntStream<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[],"_links":{"self":[{"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=\/wp\/v2\/posts\/516"}],"collection":[{"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=516"}],"version-history":[{"count":3,"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=\/wp\/v2\/posts\/516\/revisions"}],"predecessor-version":[{"id":519,"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=\/wp\/v2\/posts\/516\/revisions\/519"}],"wp:attachment":[{"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=516"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kd2.jp\/memo3\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}