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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="17.9.htm"><img src="previous.gif" alt="previous" border="0" /></a><a href="17.9.2.htm"><img src="next.gif" alt="next" border="0" /></a></span><span class="clause-depth"><a href="16.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="18.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="17.htm">17</a></span><span class="clause-title-previous"> Classes</span></span><span class="clause-depth"><a href="17.8.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="17.10.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="17.9.htm">17.9</a></span><span class="clause-title-previous"> Operators</span></span><span class="clause-depth"><a href="17.9.1.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="17.9.2.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number">17.9.1</span><span class="clause-title"> Unary operators</span></span><span class="locator">
Paragraph 1</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P1S1"></a>The following rules apply to unary operator declarations, where T denotes the class or struct type that contains the operator declaration: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P1S2"></a> A unary +, -, !, or ~ operator must take a single parameter of type T and can return any type.</span> </li><li><span class="sentence"><span class="sentence-number">3</span> <a name="P1S3"></a> A unary ++ or --operator must take a single parameter of type T and must return type T.</span> </li><li><span class="sentence"><span class="sentence-number">4</span> <a name="P1S4"></a> A unary true or false operator must take a single parameter of type T and must return type <span class="keyword">bool</span>.</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 signature of a unary operator consists of the operator token (+, -, !, ~, ++, --, true, or false) and the type of the single formal parameter.</span> <span class="sentence"><span class="sentence-number">2</span> <a name="P2S2"></a>The return type is not part of a unary operator's signature, nor is the name of the formal parameter.</span> </span><span class="locator">
Paragraph 3</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P3S1"></a>The true and false unary operators require pair-wise declaration.</span> <span class="sentence"><span class="sentence-number">2</span> <a name="P3S2"></a>A compile-time error occurs if a class declares one of these operators without also declaring the other.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P3S3"></a>The true and false operators are described further in <a href="14.16.htm">§14.16</a>.</span> </span><span class="paragraph"><span class="example">[Example: The following example shows an implementation and subsequent usage of operator++ for an integer vector class: <pre class="code-example">
public class IntVector
{
public int Length { ... } // read-only property
public int this[int index] { ... } // read-write indexer
public IntVector(int vectorLength) { ... }
public static IntVector operator++(IntVector iv) {
IntVector temp = new IntVector(iv.Length);
for (int i = 0; i < iv.Length; ++i)
temp[i] = iv[i] + 1;
return temp;
}
}
class Test
{
static void Main() {
IntVector iv1 = new IntVector(4); // vector of 4x0
IntVector iv2;
iv2 = iv1++; // iv2 contains 4x0, iv1 contains 4x1
iv2 = ++iv1; // iv2 contains 4x2, iv1 contains 4x2
}
</pre></span></span><span class="paragraph"><span class="example">Note how the operator method returns the value produced by adding 1 to the operand, just like the postfix increment and decrement operators(<a href="14.5.9.htm">§14.5.9</a>), and the prefix increment and decrement operators (<a href="14.6.5.htm">§14.6.5</a>). </span></span><span class="paragraph"><span class="example">Unlike in C++, this method need not, and, in fact, must not, modify the value of its operand directly. end example]</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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