function.round.html
来自「php的帮助文档,涉及到PHP的案例和基本语法,以及实际应用内容」· HTML 代码 · 共 133 行
HTML
133 行
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Rounds a float</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.rand.html">rand</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.sin.html">sin</a></div> <div class="up"><a href="ref.math.html">Math Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.round" class="refentry"> <div class="refnamediv"> <h1 class="refname">round</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">round</span> — <span class="dc-title">Rounds a float</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">float</span> <span class="methodname"><b><b>round</b></b></span> ( <span class="methodparam"><span class="type">float</span> <tt class="parameter">$val</tt></span> [, <span class="methodparam"><span class="type">int</span> <tt class="parameter">$precision</tt></span> ] )</div> <p class="para rdfs-comment"> Returns the rounded value of <i><tt class="parameter">val</tt></i> to specified <i><tt class="parameter">precision</tt></i> (number of digits after the decimal point). <i><tt class="parameter">precision</tt></i> can also be negative or zero (default). </p> <p class="para"> <blockquote><p><b class="note">Note</b>: <span class="simpara"> PHP doesn't handle strings like <i>"12,300.2"</i> correctly by default. See <a href="language.types.string.html#language.types.string.conversion" class="link">converting from strings</a>. </span> </p></blockquote> </p> <p class="para"> <blockquote><p><b class="note">Note</b>: <span class="simpara"> The <i><tt class="parameter">precision</tt></i> parameter was introduced in PHP 4. </span> </p></blockquote> </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><i><tt class="parameter">val</tt></i></span> <dd> <p class="para"> The value to round </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">precision</tt></i></span> <dd> <p class="para"> The optional number of decimal digits to round to, defaults to 0 </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> The rounded value </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 <b>round()</b> examples</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">3.4</span><span style="color: #007700">); </span><span style="color: #FF8000">// 3<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">3.5</span><span style="color: #007700">); </span><span style="color: #FF8000">// 4<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">3.6</span><span style="color: #007700">); </span><span style="color: #FF8000">// 4<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">3.6</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">); </span><span style="color: #FF8000">// 4<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">1.95583</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">); </span><span style="color: #FF8000">// 1.96<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">1241757</span><span style="color: #007700">, -</span><span style="color: #0000BB">3</span><span style="color: #007700">); </span><span style="color: #FF8000">// 1242000<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">5.045</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">); </span><span style="color: #FF8000">// 5.05<br /></span><span style="color: #007700">echo </span><span style="color: #0000BB">round</span><span style="color: #007700">(</span><span style="color: #0000BB">5.055</span><span style="color: #007700">, </span><span style="color: #0000BB">2</span><span style="color: #007700">); </span><span style="color: #FF8000">// 5.06<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </div> </p> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.ceil.html" class="function" rel="rdfs-seeAlso">ceil()</a></li> <li class="member"><a href="function.floor.html" class="function" rel="rdfs-seeAlso">floor()</a></li> <li class="member"><a href="function.number-format.html" class="function" rel="rdfs-seeAlso">number_format()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.rand.html">rand</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.sin.html">sin</a></div> <div class="up"><a href="ref.math.html">Math Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?