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Hex string to Float (32bit) IEEE 754
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| <html> | |
| <head> | |
| <script> | |
| /* | |
| Converts a 32bit HEX string (42883EFA) to Float 68.1229476928711 | |
| Complies to IEEE 754 Standards. | |
| Tested with a range of sample inputs. Feel free to report a bug. | |
| */ | |
| function HexStr2Dec(str) // Converts the string into an actual array of 4bit decimal values (Hex values) | |
| { | |
| var res = []; | |
| str = str.toUpperCase(); | |
| var len = str.length; | |
| for(var i = 0; i < len; i++) | |
| { | |
| var chc = str[i].charCodeAt(0); | |
| if( chc >= 48 && chc <= 57 ) | |
| { | |
| res.push(chc - 48); | |
| } | |
| else if( chc >= 65 && chc <= 70 ) | |
| { | |
| res.push(chc - 55); | |
| } | |
| } | |
| return res; | |
| } | |
| function Byte2Float(num) //4 byte float input conversion | |
| { | |
| var sign = ((num[0] >> 4) & 8)/8; | |
| var exp = ((((num[0] * 256) + num[1]) & 0x7F80 ) >> 7) - 127; | |
| var significand = ((num[1] * 65536 + num[2] * 256 + num[3]) & 8388607).toString(2); | |
| var frac = 1; | |
| var max = 23; | |
| for(var i = (significand.length-1); i >= 0; i--) | |
| { | |
| frac += (significand[i] / Math.pow(2,max)); | |
| max--; | |
| } | |
| var res = Math.pow(-1,sign) * frac * Math.pow(2,exp); | |
| return res; | |
| } | |
| function Binary2Float(num) //Takes an 4 bit Integer array (length of 8), which read as binary for bit wise calculations. | |
| { | |
| var sign = (num[0] & 8)/8; | |
| var exp = (((num[0] * 256 + num[1] * 16 + num[2]) & 2040) >> 3) - 127; | |
| var significand = ((num[2] * 1048576 + num[3] * 65536 + num[4] * 4096 + num[5] * 256 + num[6] * 16 + num[7]) & 8388607).toString(2); | |
| var frac = 1; | |
| var max = 23; | |
| for(var i = (significand.length-1); i >= 0; i--) | |
| { | |
| frac += (significand[i] / Math.pow(2,max)); | |
| max--; | |
| } | |
| var res = Math.pow(-1,sign) * frac * Math.pow(2,exp); | |
| return res; | |
| } | |
| function calc() | |
| { | |
| var str = document.getElementById("txtInput").value; | |
| document.getElementById("result").innerHTML = Binary2Float(HexStr2Dec(str)); | |
| } | |
| </script> | |
| </head> | |
| <body onload=""> | |
| <input type="text" id="txtInput"> | |
| <input type="button" value="calculate" onclick="calc()"> | |
| <div id="result"></div> | |
| </body> | |
| </html> |
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