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        <h2 id="1、-java程序的组成："><a href="#1、-java程序的组成：" class="headerlink" title="1、    java程序的组成："></a>1、    java程序的组成：</h2><p>关键字，标识符，注释，变量，语句，表达式，数组，方法</p>
<h2 id="2、-关键字："><a href="#2、-关键字：" class="headerlink" title="2、    关键字："></a>2、    关键字：</h2><p>Java语言内部使用了的一些用于特殊用途的词汇，那么在程序中用户不能使用。语言本身保留了一些词汇用于语言的语法等用途。<br><img src="http://ou3xxg3hg.bkt.clouddn.com/关键字.jpg" alt=""></p>
<h2 id="3、-已用到的关键字："><a href="#3、-已用到的关键字：" class="headerlink" title="3、    已用到的关键字："></a>3、    已用到的关键字：</h2><p>class 声明一个类。<br>public: 表示该类可以被外界调用  如果一个类被声明为public,那么该类所在的文件名要和类名一致。编译后的文件名和类名相同。<br>static:表示是静态的。<br>void：表示没有返回值<br><a id="more"></a></p>
<h2 id="4、-关键字都是小写的。"><a href="#4、-关键字都是小写的。" class="headerlink" title="4、    关键字都是小写的。"></a>4、    关键字都是小写的。</h2><h2 id="5、-标识符："><a href="#5、-标识符：" class="headerlink" title="5、    标识符："></a>5、    标识符：</h2><p>标识符就是用户在程序自定义使用的一些名词。在程序中标识符可以用来表示类名，变量名，方法名，参数名等。<br>在java中标识符的组成：<br>大小写字母，数字，下划线以及$组成。不能以数字开头。标识符通常要有意义。不能随便乱取。建议使用英文表示。<br>类名：以大写字母开头，所有单词首字母大写。采用的Pascal命名规则<br>变量名：第一个单词首字母以小写开头，其后的所有单词首字母以大写开头。采用的驼峰命名规则。</p>
<h2 id="6、-注释："><a href="#6、-注释：" class="headerlink" title="6、    注释："></a>6、    注释：</h2><p>在程序中，方便人们阅读代码而写的一些说明文字。<br>在java中有3类注释：<br>单行注释：用// 开头<br>多行注释：用/<em>开头  </em>/结尾<br>文档注释：用/<em>* 开头  </em>/结尾，并且在其中会用到一些java定义好的注解来声明<br>注意：单行注释和多行注释不会被编译 也不会被jvm解释执行，文档注释会编译，可以通过jvm生成对应的html文档,方便用户查询使用。</p>
<h2 id="7、-总结："><a href="#7、-总结：" class="headerlink" title="7、    总结："></a>7、    总结：</h2><p>第一条：常用的关键字要熟悉，能够记住。<br>第二条：标识符的命名要符合规范。<br>第三条：程序一定要注释。建议先写注释，再写代码。</p>


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