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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="15.8.2.htm"><img src="previous.gif" alt="previous" border="0" /></a><a href="15.8.4.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="15.7.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="15.9.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number-link"><a href="15.8.htm">15.8</a></span><span class="clause-title-previous"> Iteration statements</span></span><span class="clause-depth"><a href="15.8.2.htm"><img src="previous.gif" alt="previous at this level" border="0" /></a><a href="15.8.4.htm"><img src="next.gif" alt="next at this level" border="0" /></a> <span class="clause-number">15.8.3</span><span class="clause-title"> The for 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 for statement evaluates a sequence of initialization expressions and then, while a condition is true, repeatedly executes an embedded statement and evaluates a sequence of iteration expressions.</span> <span class="grammar-production"><span class="name"><a name="for-statement"></a>for-statement</span> : <span class="rhs"><span class="keyword">for</span> <span class="terminal">(</span> <span class="non-terminal"><a href="15.8.3.htm#for-initializer">for-initializer</a></span><sub>opt</sub> <span class="terminal">;</span> <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span><sub>opt</sub> <span class="terminal">;</span> <span class="non-terminal"><a href="15.8.3.htm#for-iterator">for-iterator</a></span><sub>opt</sub> <span class="terminal">)</span> <span class="non-terminal"><a href="15.htm#embedded-statement">embedded-statement</a></span> </span></span><span class="grammar-production"><span class="name"><a name="for-initializer"></a>for-initializer</span> : <span class="rhs"><span class="non-terminal"><a href="15.5.1.htm#local-variable-declaration">local-variable-declaration</a></span> </span><span class="rhs"><span class="non-terminal"><a href="15.8.3.htm#statement-expression-list">statement-expression-list</a></span> </span></span><span class="grammar-production"><span class="name"><a name="for-condition"></a>for-condition</span> : <span class="rhs"><span class="non-terminal"><a href="15.7.1.htm#boolean-expression">boolean-expression</a></span> </span></span><span class="grammar-production"><span class="name"><a name="for-iterator"></a>for-iterator</span> : <span class="rhs"><span class="non-terminal"><a href="15.8.3.htm#statement-expression-list">statement-expression-list</a></span> </span></span><span class="grammar-production"><span class="name"><a name="statement-expression-list"></a>statement-expression-list</span> : <span class="rhs"><span class="non-terminal"><a href="15.6.htm#statement-expression">statement-expression</a></span> </span><span class="rhs"><span class="non-terminal"><a href="15.8.3.htm#statement-expression-list">statement-expression-list</a></span> <span class="terminal">,</span> <span class="non-terminal"><a href="15.6.htm#statement-expression">statement-expression</a></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>The <span class="non-terminal"><a href="15.8.3.htm#for-initializer">for-initializer</a></span>, if present, consists of either a <span class="non-terminal"><a href="15.5.1.htm#local-variable-declaration">local-variable-declaration</a></span> (<a href="15.5.1.htm">§15.5.1</a>) or a list of <span class="non-terminal"><a href="15.6.htm#statement-expression">statement-expression</a></span>s (<a href="15.6.htm">§15.6</a>) separated by commas.</span> <span class="sentence"><span class="sentence-number">2</span> <a name="P2S2"></a>The scope of a local variable declared by a <span class="non-terminal"><a href="15.8.3.htm#for-initializer">for-initializer</a></span> starts at the <span class="non-terminal"><a href="15.5.1.htm#local-variable-declarator">local-variable-declarator</a></span> for the variable and extends to the end of the embedded statement.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P2S3"></a>The scope includes the <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> and the <span class="non-terminal"><a href="15.8.3.htm#for-iterator">for-iterator</a></span>.</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 <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span>, if present, must be a <span class="non-terminal"><a href="15.7.1.htm#boolean-expression">boolean-expression</a></span> (<a href="14.16.htm">§14.16</a>).</span> </span><span class="locator">
Paragraph 4</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P4S1"></a>The <span class="non-terminal"><a href="15.8.3.htm#for-iterator">for-iterator</a></span>, if present, consists of a list of <span class="non-terminal"><a href="15.6.htm#statement-expression">statement-expression</a></span>s (<a href="15.6.htm">§15.6</a>) separated by commas.</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 for statement is executed as follows: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P5S2"></a> If a <span class="non-terminal"><a href="15.8.3.htm#for-initializer">for-initializer</a></span> is present, the variable initializers or statement expressions are executed in the order they are written.</span> <span class="sentence"><span class="sentence-number">3</span> <a name="P5S3"></a>This step is only performed once.</span> </li><li><span class="sentence"><span class="sentence-number">4</span> <a name="P5S4"></a> If a <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> is present, it is evaluated.</span> </li><li><span class="sentence"><span class="sentence-number">5</span> <a name="P5S5"></a> If the <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> is not present or if the evaluation yields true, control is transferred to the embedded statement.</span> <span class="sentence"><span class="sentence-number">6</span> <a name="P5S6"></a>When and if control reaches the end point of the embedded statement (possibly from execution of a continue statement), the expressions of the <span class="non-terminal"><a href="15.8.3.htm#for-iterator">for-iterator</a></span>, if any, are evaluated in sequence, and then another iteration is performed, starting with evaluation of the <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> in the step above.</span> </li><li><span class="sentence"><span class="sentence-number">7</span> <a name="P5S7"></a> If the <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> is present and the evaluation yields false, control is transferred to the end point of the for statement.</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>Within the embedded statement of a for statement, a break statement (<a href="15.9.1.htm">§15.9.1</a>) may be used to transfer control to the end point of the for statement (thus ending iteration of the embedded statement), and a continue statement (<a href="15.9.2.htm">§15.9.2</a>) may be used to transfer control to the end point of the embedded statement (thus executing another iteration of the for statement).</span> </span><span class="locator">
Paragraph 7</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P7S1"></a>The embedded statement of a for statement is reachable if one of the following is true: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P7S2"></a> The for statement is reachable and no <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> is present.</span> </li><li><span class="sentence"><span class="sentence-number">3</span> <a name="P7S3"></a> The for statement is reachable and a <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> is present and does not have the constant value false.</span> </li></ul></span><span class="locator">
Paragraph 8</span><span class="paragraph"><span class="sentence"><span class="sentence-number">1</span> <a name="P8S1"></a>The end point of a for statement is reachable if at least one of the following is true: </span><ul><li><span class="sentence"><span class="sentence-number">2</span> <a name="P8S2"></a> The for statement contains a reachable break statement that exits the for statement.</span> </li><li><span class="sentence"><span class="sentence-number">3</span> <a name="P8S3"></a> The for statement is reachable and a <span class="non-terminal"><a href="15.8.3.htm#for-condition">for-condition</a></span> is present and does not have the constant value true.</span> </li></ul></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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