📄 15.9.4.htm
字号:
<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="15.9.3.htm"><img src="previous.gif" alt="previous" border="0" /></a><a href="15.9.5.htm"><img src="next.gif" alt="next" border="0" /></a></span><span class="clause-depth"><a href="14.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="16.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="15.htm">15</a></span><span class="clause-title-previous"> Statements</span></span><span class="clause-depth"><a href="15.8.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="15.10.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="15.9.htm">15.9</a></span><span class="clause-title-previous"> Jump statements</span></span><span class="clause-depth"><a href="15.9.3.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="15.9.5.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number">15.9.4</span><span class="clause-title"> The return statement</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 return statement returns control to the caller of the function member in which the return statement appears.</span> <span class="grammar-production"><span class="name"><a name="return-statement"></a>return-statement</span> : <span class="rhs"><span class="keyword">return</span> <span class="non-terminal"><a href="14.14.htm#expression">expression</a></span><sub>opt</sub> <span class="terminal">;</span> </span></span></span><span class="locator">
Paragraph 2</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P2S1"></a>A return statement with no expression can be used only in a function member that does not compute a value; that is, a method with the return type <span class="keyword">void</span>, the set accessor of a property or indexer, the add and remove accessors of an event, an instance constructor, static constructor, or a destructor.</span> </span><span class="locator">
Paragraph 3</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P3S1"></a>A return statement with an expression can only be used in a function member that computes a value, that is, a method with a non-void return type, the get accessor of a property or indexer, or a user-defined operator.</span> <span class="sentence"><span class="sentence-number">2</span> <a name="P3S2"></a>An implicit conversion (<a href="13.1.htm">§13.1</a>) must exist from the type of the expression to the return type of the containing function member.</span> </span><span class="locator">
Paragraph 4</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P4S1"></a>It is a compile-time error for a return statement to appear in a finally block (<a href="15.10.htm">§15.10</a>).</span> </span><span class="locator">
Paragraph 5</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P5S1"></a>A return statement is executed as follows: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P5S2"></a> If the return statement specifies an expression, the expression is evaluated and the resulting value is converted to the return type of the containing function member by an implicit conversion.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P5S3"></a>The result of the conversion becomes the value returned to the caller.</span> </li><li><span class="sentence"><span class="sentence-number">4</span> <a name="P5S4"></a> If the return statement is enclosed by one or more try blocks with associated finally blocks, control is initially transferred to the finally block of the innermost try statement.</span> <span class="sentence"><span class="sentence-number">5</span> <a name="P5S5"></a>When and if control reaches the end point of a finally block, control is transferred to the finally block of the next enclosing try statement.</span> <span class="sentence"><span class="sentence-number">6</span> <a name="P5S6"></a>This process is repeated until the finally blocks of all enclosing try statements have been executed.</span> </li><li><span class="sentence"><span class="sentence-number">7</span> <a name="P5S7"></a> Control is returned to the caller of the containing function member.</span> </li></ul></span><span class="locator">
Paragraph 6</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P6S1"></a>Because a return statement unconditionally transfers control elsewhere, the end point of a return statement is never reachable.</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
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -