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<div align="center" class="title">JAVA程序员必读：基础篇（3）语言基础</div>
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<div align="center"><font color="#666666">编译：ZSC/太平洋网络学院</font></div>
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<div align="right" class="gray"><a href="mailto:tntst@pconline.com.cn">［责编:爆破手］</a></div>
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<p class="article"> <b>语言基础</b> </p>
<p> </p>
<p><b><span class="article">3.1.5 </span></b><span class="article"><b>变量的总结</b></span></p>
<p class="article"> 当你声明了一个变量，你就显性地设置了变量的名字和数据类型。JAVA编程语言右两类的数据类型：原始和引用。原始数据的变量包含一个数值。以下这张表显示了所有的原始数据类型以及它们的大小和格式。</p>
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<p align="CENTER" class="article">关键字
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<p align="CENTER" class="article">描述
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<p align="CENTER" class="article">大小/格式
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<p align="CENTER" class="article">整型
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<p align="CENTER" class="article">byte
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<p align="CENTER" class="article">字节长度整型
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<p align="CENTER" class="article">8位两个补码
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<p align="CENTER" class="article">Short
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<p align="CENTER" class="article">短整型
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<p align="CENTER" class="article">16位两个补码
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<p align="CENTER" class="article">int
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<p align="CENTER" class="article">整型
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<p align="CENTER" class="article">32位两个补码
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<p align="CENTER" class="article">long
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<p align="CENTER" class="article">64位两个补码
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<p align="CENTER" class="article">实数
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<p align="CENTER" class="article">Float
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<p align="CENTER" class="article">单精度浮点型
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<p align="CENTER" class="article">32位IEEE 754
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<p align="CENTER" class="article">双精度浮点型
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<p align="CENTER" class="article">64位IEEE 754
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<p align="CENTER" class="article">其它类型
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<p align="CENTER" class="article">16位Unicode字符
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<p align="CENTER" class="article">boolean
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<p align="CENTER" class="article">布尔型数值（true或者false）
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<p align="CENTER" class="article">真或假
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<p class="article"> 变量声明的位置隐含地设置了变量的作用域，它决定了代码的哪一部分可以通过变量名来调用这个变量。具体有以下四种类型的作用域：成员变量作用域、本地变量作用域、参数作用域以及异常处理参数作用域。</p>
<p class="article"> 你可以使用赋值操作符（=）来在声明的地方对变量进行初始化。</p>
<p class="article"> 你也可以将变量声明为final。Final变量的数值在初始化之后不能再被改变。</p>
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