{"componentChunkName":"component---src-templates-post-template-jsx","path":"/history/posts/2020-10-04--002","result":{"data":{"site":{"siteMetadata":{"title":"Blog by Eunyoung","subtitle":"작업 기록 블로그","copyright":"© All rights reserved.","author":{"name":"EunYoung","twitter":"#"},"disqusShortname":"","url":"https://ssongey.github.io"}},"markdownRemark":{"id":"d2a48559-4e48-5b7e-9798-fa5819388191","html":"<h2>객체(Object) 란?</h2>\n<ul>\n<li>자신의 속성과 동작을 가진 모든 것</li>\n<li>\n<p>객체 vs 인스턴스<br>\n— 객체는 선언을 의미\n— 인스턴스는 연산자를 통해 클래스로부터 실체화가 됨을 의미</p>\n<div class=\"gatsby-highlight\" data-language=\"text\"><pre class=\"language-text\"><code class=\"language-text\">class Car { ... }\nCar tico, morning, matiz; // 객체\ntico = new Car(); // 인스턴스</code></pre></div>\n<h5>참고</h5>\n<p><a href=\"https://dbnsecu.tistory.com/8\">https://dbnsecu.tistory.com/8</a><br>\n<a href=\"https://gmlwjd9405.github.io/2018/09/17/class-object-instance.html\">https://gmlwjd9405.github.io/2018/09/17/class-object-instance.html</a></p>\n</li>\n</ul>\n<h2>객체간의 관계</h2>\n<h4>관계의 종류</h4>\n<ul>\n<li>집합 관계: 완성품과 부품의 관계</li>\n<li>사용 관계: 객체가 다른 객체를 사용하는 관계</li>\n<li>상속 관계: 종류 객체와  구체적인 사물 객체 관계\n\n  <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/devHistoryBlog/static/e1dea42cb4af4f90f96507f339214fe4/d0e73/002--1.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n  \n  <span\n    class=\"gatsby-resp-image-wrapper\"\n    style=\"position: relative; display: block;  max-width: 671px; margin-left: auto; margin-right: auto;\"\n  >\n    <span\n      class=\"gatsby-resp-image-background-image\"\n      style=\"padding-bottom: 79.58333333333334%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n    >\n      <img\n        class=\"gatsby-resp-image-image\"\n        style=\"width: 100%; height: 100%; margin: 0; vertical-align: middle; position: absolute; top: 0; left: 0; box-shadow: inset 0px 0px 0px 400px white;\"\n        alt=\"002  1\"\n        title=\"\"\n        src=\"/devHistoryBlog/static/e1dea42cb4af4f90f96507f339214fe4/d0e73/002--1.png\"\n        srcset=\"/devHistoryBlog/static/e1dea42cb4af4f90f96507f339214fe4/8ff5a/002--1.png 240w,\n/devHistoryBlog/static/e1dea42cb4af4f90f96507f339214fe4/e85cb/002--1.png 480w,\n/devHistoryBlog/static/e1dea42cb4af4f90f96507f339214fe4/d0e73/002--1.png 671w\"\n        sizes=\"(max-width: 671px) 100vw, 671px\"\n      />\n    </span>\n  </span>\n  \n  </a>\n    </li>\n</ul>\n<h2>클래스 변수</h2>\n<ul>\n<li>new 연산자에 의해 리턴 된 객체의 번지 저장 (참조 타입 변수)</li>\n<li>힙 영역의 객체를 사용하기 위해 사용\n\n  <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/devHistoryBlog/static/997e6001c610902d915bc718a2946957/7de01/002--2.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n  \n  <span\n    class=\"gatsby-resp-image-wrapper\"\n    style=\"position: relative; display: block;  max-width: 794px; margin-left: auto; margin-right: auto;\"\n  >\n    <span\n      class=\"gatsby-resp-image-background-image\"\n      style=\"padding-bottom: 24.583333333333336%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n    >\n      <img\n        class=\"gatsby-resp-image-image\"\n        style=\"width: 100%; height: 100%; margin: 0; vertical-align: middle; position: absolute; top: 0; left: 0; box-shadow: inset 0px 0px 0px 400px white;\"\n        alt=\"002  2\"\n        title=\"\"\n        src=\"/devHistoryBlog/static/997e6001c610902d915bc718a2946957/7de01/002--2.png\"\n        srcset=\"/devHistoryBlog/static/997e6001c610902d915bc718a2946957/8ff5a/002--2.png 240w,\n/devHistoryBlog/static/997e6001c610902d915bc718a2946957/e85cb/002--2.png 480w,\n/devHistoryBlog/static/997e6001c610902d915bc718a2946957/7de01/002--2.png 794w\"\n        sizes=\"(max-width: 794px) 100vw, 794px\"\n      />\n    </span>\n  </span>\n  \n  </a>\n    </li>\n</ul>\n<h2>인스턴스 멤버</h2>\n<ul>\n<li>인스턴스 생성 시 아래와 같은 메모리 구조를 갖는다.\n\n  <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/devHistoryBlog/static/fa559797bc9942acb2507cb85da0e734/0f79a/002--3.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n  \n  <span\n    class=\"gatsby-resp-image-wrapper\"\n    style=\"position: relative; display: block;  max-width: 689px; margin-left: auto; margin-right: auto;\"\n  >\n    <span\n      class=\"gatsby-resp-image-background-image\"\n      style=\"padding-bottom: 54.166666666666664%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n    >\n      <img\n        class=\"gatsby-resp-image-image\"\n        style=\"width: 100%; height: 100%; margin: 0; vertical-align: middle; position: absolute; top: 0; left: 0; box-shadow: inset 0px 0px 0px 400px white;\"\n        alt=\"002  3\"\n        title=\"\"\n        src=\"/devHistoryBlog/static/fa559797bc9942acb2507cb85da0e734/0f79a/002--3.png\"\n        srcset=\"/devHistoryBlog/static/fa559797bc9942acb2507cb85da0e734/8ff5a/002--3.png 240w,\n/devHistoryBlog/static/fa559797bc9942acb2507cb85da0e734/e85cb/002--3.png 480w,\n/devHistoryBlog/static/fa559797bc9942acb2507cb85da0e734/0f79a/002--3.png 689w\"\n        sizes=\"(max-width: 689px) 100vw, 689px\"\n      />\n    </span>\n  </span>\n  \n  </a>\n    </li>\n</ul>\n<h4>this 키워드</h4>\n<ul>\n<li>인스턴스 자신의 주소를 가지고 있는 키워드\n\n  <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/devHistoryBlog/static/965ac43876ec650ff6c4ed7f06a9fdc7/cecac/002--4.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n  \n  <span\n    class=\"gatsby-resp-image-wrapper\"\n    style=\"position: relative; display: block;  max-width: 728px; margin-left: auto; margin-right: auto;\"\n  >\n    <span\n      class=\"gatsby-resp-image-background-image\"\n      style=\"padding-bottom: 54.166666666666664%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n    >\n      <img\n        class=\"gatsby-resp-image-image\"\n        style=\"width: 100%; height: 100%; margin: 0; vertical-align: middle; position: absolute; top: 0; left: 0; box-shadow: inset 0px 0px 0px 400px white;\"\n        alt=\"002  4\"\n        title=\"\"\n        src=\"/devHistoryBlog/static/965ac43876ec650ff6c4ed7f06a9fdc7/cecac/002--4.png\"\n        srcset=\"/devHistoryBlog/static/965ac43876ec650ff6c4ed7f06a9fdc7/8ff5a/002--4.png 240w,\n/devHistoryBlog/static/965ac43876ec650ff6c4ed7f06a9fdc7/e85cb/002--4.png 480w,\n/devHistoryBlog/static/965ac43876ec650ff6c4ed7f06a9fdc7/cecac/002--4.png 728w\"\n        sizes=\"(max-width: 728px) 100vw, 728px\"\n      />\n    </span>\n  </span>\n  \n  </a>\n    </li>\n</ul>\n<h2>정적 멤버와 static</h2>\n<h4>정적(static) 멤버란?</h4>\n<ul>\n<li>클래스에 고정된 필드와 메소드 - 정적 필드, 정적 메소드</li>\n<li>정적 멤버는 클래스에 소속된 멤버<br>\n— 객체 내부에 존재하지 않고, 메소드 영역에 존재<br>\n— 정적 멤버는 객체를 생성하지 않고 클래스로 바로 접근해 사용\n\n  <a\n    class=\"gatsby-resp-image-link\"\n    href=\"/devHistoryBlog/static/fd66c6c2551992959f6abddb8bea5bb4/7fee5/002--5.png\"\n    style=\"display: block\"\n    target=\"_blank\"\n    rel=\"noopener\"\n  >\n  \n  <span\n    class=\"gatsby-resp-image-wrapper\"\n    style=\"position: relative; display: block;  max-width: 781px; margin-left: auto; margin-right: auto;\"\n  >\n    <span\n      class=\"gatsby-resp-image-background-image\"\n      style=\"padding-bottom: 27.500000000000004%; position: relative; bottom: 0; left: 0; background-image: url('data:image/png;base64,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'); background-size: cover; display: block;\"\n    >\n      <img\n        class=\"gatsby-resp-image-image\"\n        style=\"width: 100%; height: 100%; margin: 0; vertical-align: middle; position: absolute; top: 0; left: 0; box-shadow: inset 0px 0px 0px 400px white;\"\n        alt=\"002  5\"\n        title=\"\"\n        src=\"/devHistoryBlog/static/fd66c6c2551992959f6abddb8bea5bb4/7fee5/002--5.png\"\n        srcset=\"/devHistoryBlog/static/fd66c6c2551992959f6abddb8bea5bb4/8ff5a/002--5.png 240w,\n/devHistoryBlog/static/fd66c6c2551992959f6abddb8bea5bb4/e85cb/002--5.png 480w,\n/devHistoryBlog/static/fd66c6c2551992959f6abddb8bea5bb4/7fee5/002--5.png 781w\"\n        sizes=\"(max-width: 781px) 100vw, 781px\"\n      />\n    </span>\n  </span>\n  \n  </a>\n    </li>\n</ul>\n<h4>정적 초기화 블록</h4>\n<ul>\n<li>클래스가 메소드 영역으로 로딩될 때 자동으로 실행하는 블록</li>\n<li>정적 필드 초기화 및 정적 메소드 호출 가능</li>\n<li>\n<p>인스턴스 멤버나 메소드 호출 불가능</p>\n<div class=\"gatsby-highlight\" data-language=\"text\"><pre class=\"language-text\"><code class=\"language-text\">static {\n...\n}</code></pre></div>\n</li>\n</ul>\n<h4>Annotation</h4>","fields":{"tagSlugs":["/tags/책리뷰/"],"slug":"/history/posts/2020-10-04--002"},"frontmatter":{"title":"[Java] Class","tags":["책리뷰"],"date":"2020-10-04","description":""}}},"pageContext":{"slug":"/history/posts/2020-10-04--002"}},"staticQueryHashes":[]}