class="markdown_views prism-atom-one-light">

public

1、public：public表明该数据成员、成员函数是对所有用户开放的，所有用户都可以直接进行调用 。

class="prism language-class="tags" href="/tags/JAVA.html" title=java>java">class="token keyword">package comclass="token punctuation">.mtlkclass="token punctuation">.day_03class="token punctuation">;

class="token keyword">public class="token keyword">class class="token class-name">Students class="token punctuation">{
    String nameclass="token punctuation">;
    class="token keyword">int ageclass="token punctuation">;
class="token punctuation">}

在学生class="tags" href="/tags/Lei.html" title=类>类里面不加修饰符定义name和age。

class="prism language-class="tags" href="/tags/JAVA.html" title=java>java">class="token keyword">package comclass="token punctuation">.mtlkclass="token punctuation">.day_03class="token punctuation">;

class="token keyword">public class="token keyword">class class="token class-name">MyClass class="token punctuation">{
    class="token keyword">public class="token keyword">static class="token keyword">void class="token function">mainclass="token punctuation">(Stringclass="token punctuation">[class="token punctuation">] argsclass="token punctuation">)class="token punctuation">{

        Students st class="token operator">= class="token keyword">new class="token class-name">Studentsclass="token punctuation">(class="token punctuation">)class="token punctuation">;
        stclass="token punctuation">.name class="token operator">= class="token string">"try"class="token punctuation">;
        stclass="token punctuation">.age class="token operator">= class="token number">18class="token punctuation">;
        Systemclass="token punctuation">.outclass="token punctuation">.class="token function">printlnclass="token punctuation">(stclass="token punctuation">.nameclass="token operator">+class="token string">" "class="token operator">+stclass="token punctuation">.ageclass="token punctuation">)class="token punctuation">;
    class="token punctuation">}
class="token punctuation">}

在MyClass这个class="tags" href="/tags/Lei.html" title=类>类里面可以直接调用name和age。

private

2、private：private表示私有，私有的意思就是除了class自己之外，任何人都不可以直接使用，私有财产神圣不可侵犯，即便是子女，朋友，都不可以使用。

class="prism language-class="tags" href="/tags/JAVA.html" title=java>java">class="token keyword">package comclass="token punctuation">.mtlkclass="token punctuation">.day_03class="token punctuation">;

class="token keyword">public class="token keyword">class class="token class-name">Students class="token punctuation">{
    class="token keyword">private String nameclass="token punctuation">;
    class="token keyword">private class="token keyword">int  ageclass="token punctuation">;
class="token punctuation">}

在Studentclass="tags" href="/tags/Lei.html" title=类>类里面加上private修饰符

这个时候，看到MyClass.class="tags" href="/tags/JAVA.html" title=java>java会发现报错。private 只能在自己的class="tags" href="/tags/Lei.html" title=类>类了里面使用 只能在Students class="tags" href="/tags/Lei.html" title=类>类里面使用。

静态方法和非静态方法的调用

静态方法和属性用class="tags" href="/tags/Lei.html" title=类>类名调用
非静态方法和属性用引用名调用
调用符号就是一个点“.” 调用名或class="tags" href="/tags/Lei.html" title=类>类名在前，被调用的方法或属性名在后
class="tags" href="/tags/Lei.html" title=类>类型 引用名 = new 构造方法();
调用方法或构造方法必须和形参的class="tags" href="/tags/Lei.html" title=类>类型、个数、顺序一致
是不是静态看有没有static修饰
调用哪个class="tags" href="/tags/Lei.html" title=类>类的方法或属性就去实例化哪个class="tags" href="/tags/Lei.html" title=类>类

class="prism language-class="tags" href="/tags/JAVA.html" title=java>java">class="token keyword">package meclass="token punctuation">;
class="token keyword">public class="token keyword">class class="token class-name">Book class="token punctuation">{   class="token comment">//定义一个classclass="tags" href="/tags/Lei.html" title=类>类 book 全局的
    class="token keyword">public class="token keyword">void class="token function">infoclass="token punctuation">(class="token punctuation">) class="token punctuation">{ class="token comment">//定义一个非静态方法 info
        String name class="token operator">= class="token string">"英语"class="token punctuation">; class="token comment">//局部变量
        Systemclass="token punctuation">.outclass="token punctuation">.class="token function">printlnclass="token punctuation">(nameclass="token punctuation">)class="token punctuation">;
    class="token punctuation">}
 
    class="token keyword">public class="token keyword">static class="token keyword">void class="token function">meclass="token punctuation">(class="token punctuation">)class="token punctuation">{   class="token comment">//定义一个静态方法 me
        String name class="token operator">= class="token string">"数学"class="token punctuation">;
        Systemclass="token punctuation">.outclass="token punctuation">.class="token function">printlnclass="token punctuation">(nameclass="token punctuation">)class="token punctuation">;
    class="token punctuation">}
    class="token keyword">public class="token keyword">static class="token keyword">void class="token function">mainclass="token punctuation">(Stringclass="token punctuation">[class="token punctuation">] argsclass="token punctuation">) class="token punctuation">{     class="token comment">// 定义一个主函数 main 
        Book book class="token operator">= class="token keyword">new class="token class-name">Bookclass="token punctuation">(class="token punctuation">)class="token punctuation">;
        bookclass="token punctuation">.class="token function">infoclass="token punctuation">(class="token punctuation">)class="token punctuation">; class="token comment">//非静态方法调用 info  对象名.方法()
 
        Bookclass="token punctuation">.class="token function">meclass="token punctuation">(class="token punctuation">)class="token punctuation">; class="token comment">//静态方法调用 me  class="tags" href="/tags/Lei.html" title=类>类名.方法()      
    class="token punctuation">}
class="token punctuation">}