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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="14.2.6.1.htm"><img src="previous.gif" alt="previous" border="0" /></a><a href="14.3.htm"><img src="next.gif" alt="next" border="0" /></a></span><span class="clause-depth"><a href="13.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="15.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="14.htm">14</a></span><span class="clause-title-previous"> Expressions</span></span><span class="clause-depth"><a href="14.1.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="14.3.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="14.2.htm">14.2</a></span><span class="clause-title-previous"> Operators</span></span><span class="clause-depth"><a href="14.2.5.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="14.2.6.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="14.2.6.htm">14.2.6</a></span><span class="clause-title-previous"> Numeric promotions</span></span><span class="clause-depth"><a href="14.2.6.1.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="14.2.6.2.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number">14.2.6.2</span><span class="clause-title"> Binary numeric promotions</span></span><span class="informative"><span class="paragraph">This clause is informative. </span><span class="paragraph">Binary numeric promotion occurs for the operands of the predefined +, -, *, /, %, &, |, ^, ==, !=, >, <, >=, and <= binary operators. Binary numeric promotion implicitly converts both operands to a common type which, in case of the non-relational operators, also becomes the result type of the operation. Binary numeric promotion consists of applying the following rules, in the order they appear here: <ul><li> If either operand is of type <span class="keyword">decimal</span>, the other operand is converted to type <span class="keyword">decimal</span>, or a compile-time error occurs if the other operand is of type <span class="keyword">float</span> or <span class="keyword">double</span>. </li><li> Otherwise, if either operand is of type <span class="keyword">double</span>, the other operand is converted to type <span class="keyword">double</span>. </li><li> Otherwise, if either operand is of type <span class="keyword">float</span>, the other operand is converted to type <span class="keyword">float</span>. </li><li> Otherwise, if either operand is of type <span class="keyword">ulong</span>, the other operand is converted to type <span class="keyword">ulong</span>, or a compile-time error occurs if the other operand is of type <span class="keyword">sbyte</span>, <span class="keyword">short</span>, <span class="keyword">int</span>, or <span class="keyword">long</span>. </li><li> Otherwise, if either operand is of type <span class="keyword">long</span>, the other operand is converted to type <span class="keyword">long</span>. </li><li> Otherwise, if either operand is of type <span class="keyword">uint</span> and the other operand is of type <span class="keyword">sbyte</span>, <span class="keyword">short</span>, or <span class="keyword">int</span>, both operands are converted to type <span class="keyword">long</span>. </li><li> Otherwise, if either operand is of type <span class="keyword">uint</span>, the other operand is converted to type <span class="keyword">uint</span>. </li><li> Otherwise, both operands are converted to type <span class="keyword">int</span>. </li></ul></span><span class="paragraph"><span class="note">[Note: Note that the first rule disallows any operations that mix the <span class="keyword">decimal</span> type with the <span class="keyword">double</span> and <span class="keyword">float</span> types. The rule follows from the fact that there are no implicit conversions between the <span class="keyword">decimal</span> type and the <span class="keyword">double</span> and <span class="keyword">float</span> types. end note]</span> </span><span class="paragraph"><span class="note">[Note: Also note that it is not possible for an operand to be of type <span class="keyword">ulong</span> when the other operand is of a signed integral type. The reason is that no integral type exists that can represent the full range of <span class="keyword">ulong</span> as well as the signed integral types. end note]</span> </span><span class="paragraph">In both of the above cases, a cast expression can be used to explicitly convert one operand to a type that is compatible with the other operand. </span><span class="paragraph"><span class="example">[Example: In the example <pre class="code-example">
decimal AddPercent(decimal x, double percent) {
return x * (1.0 + percent / 100.0);
}
</pre>a compile-time error occurs because a <span class="keyword">decimal</span> cannot be multiplied by a <span class="keyword">double</span>. The error is resolved by explicitly converting the second operand to <span class="keyword">decimal</span>, as follows: <pre class="code-example">
decimal AddPercent(decimal x, double percent) {
return x * (decimal)(1.0 + percent / 100.0);
}
</pre>end example]</span> </span><span class="paragraph">End of informative text. </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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