4.htm

javascript book

      <!--mstheme--><font face="宋体">
      <p style="line-height: 150%; margin-left: 72pt"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font size="3">从</font></span><font size="3"><span lang="EN-US">start</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">开始到</span><span lang="EN-US">end</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的字符全部返回。</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><b><font size="3"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US"><o:p>
      </o:p>
      </span></font></b></p>
      <p style="line-height: 150%"><b><font size="3"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">２</span><span lang="EN-US">)</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、算术函数的</span><span lang="EN-US">math</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">对象</span><span lang="EN-US"><o:p>
      </o:p>
      </span></font></b></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1025" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　功能：提供除加、减、乘、除以外的一引些自述运算。如对数，平方根等</span> 
      <span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">。</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1026" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　静动性：静态对象</span></font></p>
      <p style="line-height: 150%"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font size="3">（１）主要属性</font></span></p>
      <p style="line-height: 150%"><font size="3"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　　</span><span lang="EN-US">math</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">中提供了６个属性，它们是数学中经常用到的常数Ｅ、以１０为底的自然对数ＬＮ１０、以２为底的自然对数</span><span lang="EN-US">LN2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、</span><span lang="EN-US">3.14159</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的</span><span lang="EN-US">PI</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、</span><span lang="EN-US">1/2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的平方根</span><span lang="EN-US">SQRT1-2,2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的平方根为</span><span lang="EN-US">SQRT2</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">。</span></font></p>
      <p style="line-height: 150%"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font size="3">（２）主要方法</font></span></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1027" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　绝对值：</span><span lang="EN-US">abs()</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1028" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　正弦余弦值：</span><span lang="EN-US">sin(),cos()</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1029" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　反正弦反余弦</span><span lang="EN-US"> 
      :asin(), acos()</span></font></p>  
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1030" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　正切反正切：</span><span lang="EN-US">tan(),atan()</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1031" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　四舍五入：</span><span lang="EN-US">round()</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1032" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　平方根：</span><span lang="EN-US">sqrt()</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1033" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　基于几方次的值：</span><span lang="EN-US">Pow(base,exponent)</span></font></p>
      <p style="line-height: 150%; margin-left: 144pt"><span lang="EN-US"><font size="3">...</font></span></p>
      <p style="line-height: 150%"><b><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font size="3">３</font></span><font size="3"><span lang="EN-US">)</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、日期及时间对象</span><span lang="EN-US"><o:p>
      </o:p>
      </span></font></b></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1034" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　功能：提供一个有关日期和时间的对象。</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1035" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　静动性：动态性，即必须使用</span><span lang="EN-US">New</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">运算符创建一个实例。例</span><span lang="EN-US">:</span></font></p>
      <p style="line-height: 150%; margin-left: 144pt"><span lang="EN-US"><font size="3">MyDate=New  
      Date()</font></span></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US">Date</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">对象没有提供直接访问的属性。只具有获取和设置日期和时间的方法。</span></font></p>
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1036" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　日期起始值</span><span lang="EN-US">:</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">１７７０年１月１日００</span><span lang="EN-US">:</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">００</span><span lang="EN-US">:</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">００。</span></font></p>
      <p style="text-indent: -18pt; tab-stops: list 36.0pt; mso-list: l4 level1 lfo9; line-height: 150%; margin-left: 36pt"><span lang="EN-US"><font size="3">1.<span style="FONT: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  
      </span></font></span><font size="3"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">获取日期的时间方法</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1037" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getYear():   
      </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回年数</span></font></p>  
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1038" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getMonth():</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回当月号数</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1039" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getDate():   
      </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回当日号数</span></font></p>  
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1040" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getDay():</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回星期几</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1041" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getHours():</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回小时数</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1042" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getMintes(:</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回分钟数</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1043" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getSeconds():</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回秒数</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1044" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">getTime()   
      : </span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">返回毫秒数</span></font></p>  
      <p style="line-height: 150%"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><font size="3">（２）设置日期和时间：</font></span></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1045" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">setYear();</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">设置年</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1046" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">setDate():</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">设置当月号数</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1047" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">setMonth():</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">设置当月份数</span></font></p> 
      <p style="line-height: 150%; margin-left: 72pt"><font size="3"><span lang="EN-US" style="FONT-FAMILY: System"><img id="_x0000_i1048" src="Bullet3.gif" width="12" height="12"></span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">　</span><span lang="EN-US">setHours():</span><span style="FONT-FAMILY: 宋体; mso-ascii-