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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>Hyperlinked ECMA C# Language Specification</title><meta name="author" content="Jon Jagger" /><link rel="stylesheet" href="ecma334.css"></link></head><body><div align="right"><em><a href="http://www.jaggersoft.com">Jon Jagger</a></em></div><div align="right"><a href="mailto:jon@jaggersoft.com">jon@jaggersoft.com</a></div><form method="get" action="http://search.atomz.com/search/"><input size="30" name="sp-q"></input><input type="submit" value="Search C# Spec"></input><input type="hidden" name="sp-a" value="sp10024177"></input><input type="hidden" name="sp-f" value="ISO-8859-1"></input></form><a href="toc.htm">Table of Contents</a> <a href="1.htm">1</a> <a href="2.htm">2</a> <a href="3.htm">3</a> <a href="4.htm">4</a> <a href="5.htm">5</a> <a href="6.htm">6</a> <a href="7.htm">7</a> <a href="8.htm">8</a> <a href="9.htm">9</a> <a href="10.htm">10</a> <a href="11.htm">11</a> <a href="12.htm">12</a> <a href="13.htm">13</a> <a href="14.htm">14</a> <a href="15.htm">15</a> <a href="16.htm">16</a> <a href="17.htm">17</a> <a href="18.htm">18</a> <a href="19.htm">19</a> <a href="20.htm">20</a> <a href="21.htm">21</a> <a href="22.htm">22</a> <a href="23.htm">23</a> <a href="24.htm">24</a> <a href="25.htm">25</a> <a href="notes.htm">Notes</a> <a href="HyperlinkedCSharpECMA.zip">Download</a><span class="ruler"></span><span class="heading">ECMA-334 C# Language Specification</span><span class="navigate"><a href="11.1.3.htm"><img src="previous.gif" alt="previous" border="0" /></a><a href="11.1.5.htm"><img src="next.gif" alt="next" border="0" /></a></span><span class="clause-depth"><a href="10.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="12.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="11.htm">11</a></span><span class="clause-title-previous"> Types</span></span><span class="clause-depth"><a href="11.1.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="11.2.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="11.1.htm">11.1</a></span><span class="clause-title-previous"> Value types</span></span><span class="clause-depth"><a href="11.1.3.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="11.1.5.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number">11.1.4</span><span class="clause-title"> Integral types</span></span><span class="locator">
Paragraph 1</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P1S1"></a>C# supports nine integral types: <span class="keyword">sbyte</span>, <span class="keyword">byte</span>, <span class="keyword">short</span>, <span class="keyword">ushort</span>, <span class="keyword">int</span>, <span class="keyword">uint</span>, <span class="keyword">long</span>, <span class="keyword">ulong</span>, and <span class="keyword">char</span>.</span> <span class="sentence"><span class="sentence-number">2</span> <a name="P1S2"></a>The integral types have the following sizes and ranges of values: </span><ul><li><span class="sentence"><span class="sentence-number">3</span> <a name="P1S3"></a> The <span class="keyword">sbyte</span> type represents signed 8-bit integers with values between -128 and 127.</span> </li><li><span class="sentence"><span class="sentence-number">4</span> <a name="P1S4"></a> The <span class="keyword">byte</span> type represents unsigned 8-bit integers with values between 0 and 255.</span> </li><li><span class="sentence"><span class="sentence-number">5</span> <a name="P1S5"></a> The <span class="keyword">short</span> type represents signed 16-bit integers with values between -32768 and 32767.</span> </li><li><span class="sentence"><span class="sentence-number">6</span> <a name="P1S6"></a> The <span class="keyword">ushort</span> type represents unsigned 16-bit integers with values between 0 and 65535.</span> </li><li><span class="sentence"><span class="sentence-number">7</span> <a name="P1S7"></a> The <span class="keyword">int</span> type represents signed 32-bit integers with values between -2147483648 and 2147483647.</span> </li><li><span class="sentence"><span class="sentence-number">8</span> <a name="P1S8"></a> The <span class="keyword">uint</span> type represents unsigned 32-bit integers with values between 0 and 4294967295.</span> </li><li><span class="sentence"><span class="sentence-number">9</span> <a name="P1S9"></a> The <span class="keyword">long</span> type represents signed 64-bit integers with values between -9223372036854775808 and 9223372036854775807.</span> </li><li><span class="sentence"><span class="sentence-number">10</span> <a name="P1S10"></a> The <span class="keyword">ulong</span> type represents unsigned 64-bit integers with values between 0 and 18446744073709551615.</span> </li><li><span class="sentence"><span class="sentence-number">11</span> <a name="P1S11"></a> The <span class="keyword">char</span> type represents unsigned 16-bit integers with values between 0 and 65535.</span> <span class="sentence"><span class="sentence-number">12</span> <a name="P1S12"></a>The set of possible values for the <span class="keyword">char</span> type corresponds to the Unicode character set.</span> <span class="note">[Note: Although <span class="keyword">char</span> has the same representation as <span class="keyword">ushort</span>, not all operations permitted on one type are permitted on the other. end note]</span> </li></ul></span><span class="locator">
Paragraph 2</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P2S1"></a>The <span class="non-terminal"><a href="11.1.htm#integral-type">integral-type</a></span> unary and binary operators always operate with signed 32-bit precision, unsigned 32-bit precision, signed 64-bit precision, or unsigned 64-bit precision: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P2S2"></a> For the unary + and ~ operators, the operand is converted to type T, where T is the first of <span class="keyword">int</span>, <span class="keyword">uint</span>, <span class="keyword">long</span>, and <span class="keyword">ulong</span> that can fully represent all possible values of the operand.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P2S3"></a>The operation is then performed using the precision of type T, and the type of the result is T.</span> </li><li><span class="sentence"><span class="sentence-number">4</span> <a name="P2S4"></a> For the unary -operator, the operand is converted to type T, where T is the first of <span class="keyword">int</span> and <span class="keyword">long</span> that can fully represent all possible values of the operand.</span> <span class="sentence"><span class="sentence-number">5</span> <a name="P2S5"></a>The operation is then performed using the precision of type T, and the type of the result is T.</span> <span class="sentence"><span class="sentence-number">6</span> <a name="P2S6"></a>The unary -operator cannot be applied to operands of type <span class="keyword">ulong</span>.</span> </li><li><span class="sentence"><span class="sentence-number">7</span> <a name="P2S7"></a> For the binary +, -, *, /, %, &, ^, |, ==, !=, >, <, >=, and <= operators, the operands are converted to type T, where T is the first of <span class="keyword">int</span>, <span class="keyword">uint</span>, <span class="keyword">long</span>, and <span class="keyword">ulong</span> that can fully represent all possible values of both operands.</span> <span class="sentence"><span class="sentence-number">8</span> <a name="P2S8"></a>The operation is then performed using the precision of type T, and the type of the result is T (or <span class="keyword">bool</span> for the relational operators).</span> <span class="sentence"><span class="sentence-number">9</span> <a name="P2S9"></a>It is not permitted for one operand to be of type <span class="keyword">long</span> and the other to be of type <span class="keyword">ulong</span> with the binary operators.</span> </li><li><span class="sentence"><span class="sentence-number">10</span> <a name="P2S10"></a> For the binary << and >> operators, the left operand is converted to type T, where T is the first of <span class="keyword">int</span>, <span class="keyword">uint</span>, <span class="keyword">long</span>, and <span class="keyword">ulong</span> that can fully represent all possible values of the operand.</span> <span class="sentence"><span class="sentence-number">11</span> <a name="P2S11"></a>The operation is then performed using the precision of type T, and the type of the result is T.</span> </li></ul></span><span class="locator">
Paragraph 3</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P3S1"></a>The <span class="keyword">char</span> type is classified as an integral type, but it differs from the other integral types in two ways: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P3S2"></a> There are no implicit conversions from other types to the <span class="keyword">char</span> type.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P3S3"></a>In particular, even though the <span class="keyword">sbyte</span>, <span class="keyword">byte</span>, and <span class="keyword">ushort</span> types have ranges of values that are fully representable using the <span class="keyword">char</span> type, implicit conversions from <span class="keyword">sbyte</span>, <span class="keyword">byte</span>, or <span class="keyword">ushort</span> to <span class="keyword">char</span> do not exist.</span> </li><li><span class="sentence"><span class="sentence-number">4</span> <a name="P3S4"></a> Constants of the <span class="keyword">char</span> type must be written as <span class="non-terminal"><a href="9.4.4.4.htm#character-literal">character-literal</a></span>s or as <span class="non-terminal"><a href="9.4.4.2.htm#integer-literal">integer-literal</a></span>s in combination with a cast to type <span class="keyword">char</span>.</span> <span class="example">[Example: For example, (<span class="keyword">char</span>)10 is the same as '\x000A'. end example]</span> </li></ul></span><span class="locator">
Paragraph 4</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P4S1"></a>The checked and unchecked operators and statements are used to control overflow checking for <span class="non-terminal"><a href="11.1.htm#integral-type">integral-type</a></span> arithmetic operations and conversions (<a href="14.5.12.htm">§14.5.12</a>).</span> <span class="sentence"><span class="sentence-number">2</span> <a name="P4S2"></a>In a checked context, an overflow produces a compile-time error or causes an System.OverflowException to be thrown.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P4S3"></a>In an unchecked context, overflows are ignored and any high-order bits that do not fit in the destination type are discarded.</span> </span><span class="ruler"></span><table><tr><td><table align="left" bgcolor="navy"><tr bgcolor="navy"><td><font face="Arial,sans-serif" size="6" color="yellow"><strong>{ JSL }</strong></font></td></tr></table></td></tr><tr><td><font face="Arial,sans-serif" size="2" color="navy"><strong>Jagger Software Ltd</strong></font></td></tr><tr><td><font face="Arial,sans-serif" size="2" color="navy"><strong>Company # 4070126</strong></font></td></tr><tr><td><font face="Arial,sans-serif" size="2" color="navy"><strong>VAT # 762 5213 42</strong></font></td></tr></table><img src="valid-html401.png" align="left" height="31" width="88" alt="Valid HTML 4.01" /><img src="vcss.gif" align="left" height="31" width="88" alt="Valid CSS" /></body></html>⌨️ 快捷键说明
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