IEEE 754 浮点数转换器Javascript实现 - FreeOZ论坛

<!DOCTYPE html PUBLIC "-//WEC///DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Bit Test</title>
<script type="text/javascript">
window.onload=initPage
function initPage()
{
var obj = document.getElementById('float-form');
for(var x in obj.elements)
{
if(obj.elements[x].type == 'checkbox')
{
obj.elements[x].onchange = function(){
document.getElementById('float-form').submit.click();
}
}
}
document.getElementById('float-form').onsubmit = function(){
var sign = 1;
if(this.sign.checked)
sign = -1;
var expoCheckValues = [ this.expo0, this.expo1,
this.expo2, this.expo3, this.expo4,
this.expo5, this.expo6];
var mantisseCheckValues = [ this.mant0, this.mant1, this.mant2,
this.mant3, this.mant4, this.mant5,
this.mant6, this.mant7, this.mant8,
this.mant9, this.mant10, this.mant11,
this.mant12, this.mant13, this.mant14,
this.mant15, this.mant16, this.mant17,
this.mant18, this.mant19, this.mant20,
this.mant21, this.mant22];
var expo = 0;
var mantisse = 1;
for(var k=0; k<expoCheckValues.length; ++k)
{
if(expoCheckValues[k].checked)
expo += Math.pow(2, k);
}
if(!this.expo7.checked)
expo += -127;
else
expo += 1;
for(var k=0; k<mantisseCheckValues.length; ++k)
{
if(mantisseCheckValues[k].checked)
mantisse += Math.pow(2.0, -mantisseCheckValues.length + k );
}
document.getElementById('result').innerHTML = 'exponent = ' + expo + '
'
+ 'mantisse = ' + mantisse + '
'
+ 'value = ' + ( sign * Math.pow(2, expo) * mantisse );
return false;
}
}
</script>
</head>
<body>
<p>
<form name="floatform" id="float-form" action="#" method="get">
<label>31: sign</label>: <input type="checkbox" name="sign" />
<label>30 - 23: exponent[7 - 0]</label>:<input type="checkbox" name="expo7"/>
<input type="checkbox" name="expo6"/>
<input type="checkbox" name="expo5"/>
<input type="checkbox" name="expo4"/>
<input type="checkbox" name="expo3"/>
<input type="checkbox" name="expo2"/>
<input type="checkbox" name="expo1"/>
<input type="checkbox" name="expo0"/>
<label>22 - 0: mantisse[22 - 0]</label>:<input type="checkbox" name="mant22"/>
<input type="checkbox" name="mant21"/>
<input type="checkbox" name="mant20"/>
<input type="checkbox" name="mant19"/>
<input type="checkbox" name="mant18"/>
<input type="checkbox" name="mant17"/>
<input type="checkbox" name="mant16" />
<input type="checkbox" name="mant15" />
<input type="checkbox" name="mant14" />
<input type="checkbox" name="mant13" />
<input type="checkbox" name="mant12" />
<input type="checkbox" name="mant11" />
<input type="checkbox" name="mant10" />
<input type="checkbox" name="mant9" />
<input type="checkbox" name="mant8" />
<input type="checkbox" name="mant7" />
<input type="checkbox" name="mant6" />
<input type="checkbox" name="mant5" />
<input type="checkbox" name="mant4" />
<input type="checkbox" name="mant3" />
<input type="checkbox" name="mant2" />
<input type="checkbox" name="mant1" />
<input type="checkbox" name="mant0" />
<input type="submit" name="submit" value="submit" />
</form>
</p>
<p>
<span id="result" name="result"></span>
</body>
</html>

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