下面是偶在JavaScript中实现的各种进制间的转换。

<script language="javascript">
//dh20156
//2006-9-10
//返回指定数量的重复字符组成的字符串;
function dhString(n,c){
 var tempStr = "";
 for(var i=0;i<n;i++){
  tempStr += c.toString();
 }
 return tempStr;
}

document.write("二进制、十进制转换<hr>");
//二进制 --> 十进制
function tw2teChange(n){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = 0;
 for(var i=0;i<ln;i++){
  var t = strN.substr(i,1);
  var e = ln-i-1;
  if(!isNaN(t)){
   tempInt += t*(Math.pow(2,e));
  }else{
   tempInt += "?";
  }
 }
 return tempInt;
}
function tw2te(n){
 var strN = n.toString();
 var tempInt = 0;
 var ln = strN.length;
 var ld = strN.indexOf(".")
 if(ld<0){
  tempInt = tw2teChange(strN);
 }else{
  var ti = strN.substring(0,ld);
  var tm = strN.substring(ld+1,ln);
  var tempInt1 = tw2teChange(ti);
  var tempInt2 = tw2teChange(tm);
  tempInt = tempInt1+"."+tempInt2;
 }
 return tempInt;
}
//------ 结束 -----
var a = "10110111.101100";
document.write(a+" --2T10--> "+tw2te(a)+"<br>");


//十进制 --> 二进制
function te2twChange(n){
 if(!isNaN(n) && n>0){
  if(n%2==0){
   return te2twChange(n/2)+"0";
  }else{
   if(n>2){
    return te2twChange(parseInt(n/2))+(n%2);
   }else{
    return te2twChange(0)+n;
   }
  }
 }else{
  return "";
 }
}

function te2tw(n){
 if(!isNaN(n)){
  var strN = n.toString();
  var tempInt = 0;
  var ln = strN.length;
  var ld = strN.indexOf(".")
  if(ld<0){
   tempInt = te2twChange(n);
  }else{
   var ti = strN.substring(0,ld);
   var tm = strN.substring(ld+1,ln);
   var tempInt1 = te2twChange(ti);
   var tempInt2 = te2twChange(tm);
   tempInt = tempInt1+"."+tempInt2;
  }
  return tempInt;
 }else{
  return "false";
 }
}
//------ 结束 -----
var b = 101;
document.write(b+" --10T2--> "+te2tw(b)+"<br>");
document.write("<br>二进制、八进制转换<hr>");

//二进制 --> 八进制
function tw2eiChange(n,tp){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = "";
 if(tp=="intType"){
  for(var i=ln;i>0;i -= 3){
   var tempN = strN.substring(i-3,i);
   tempInt = tw2te(tempN)+tempInt;
  }
 }else{
  for(var i=0;i<ln;i += 3){
   var tempN = strN.substring(i,i+3);
   if(tempN.length<3){
    tempN = tempN+dhString((3-tempN.length),"0");
   }
   tempInt += tw2te(tempN);
  }
 }
 return tempInt;
}

function tw2ei(n){
 var strN = n.toString();
 var tempInt = 0;
 var ln = strN.length;
 var ld = strN.indexOf(".")
 if(ld<0){
  tempInt = tw2eiChange(strN,"intType");
 }else{
  var ti = strN.substring(0,ld);
  var tm = strN.substring(ld+1,ln);
  var tempInt1 = tw2eiChange(ti,"intType");
  var tempInt2 = tw2eiChange(tm,"modType");
  tempInt = tempInt1+"."+tempInt2;
 }
 return tempInt;
}
//------ 结束 -----
var c = "10110111.1011";
document.write(c+" --2T8--> "+tw2ei(c)+"<br>");

//八进制 --> 二进制
function ei2twChange(n){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = "";
 for(var i=0;i<ln;i++){
  var t = strN.substr(i,1);
  var e = ln-i-1;
  if(!isNaN(t)){
   tempInt += te2tw(t);
  }else{
   tempInt += "?";
  }
 }
 return tempInt;
}

function ei2tw(n){
 if(!isNaN(n)){
  var strN = n.toString();
  var tempInt = 0;
  var ln = strN.length;
  var ld = strN.indexOf(".")
  if(ld<0){
   tempInt = ei2twChange(n);
  }else{
   var ti = strN.substring(0,ld);
   var tm = strN.substring(ld+1,ln);
   var tempInt1 = ei2twChange(ti);
   var tempInt2 = ei2twChange(tm);
   tempInt = tempInt1+"."+tempInt2;
  }
  return tempInt;
 }else{
  return "false";
 }
}
//------ 结束 -----
var d = 267.54;
document.write(d+" --8T2--> "+ei2tw(d)+"<br>");
document.write("<br>二进制、十六进制转换<hr>");

//二进制 <-匹配表-> 十六进制
function twMatchst(v,rv){
 if(rv==16){
  switch(v.toString()){
   case "0000":return "0";break;
   case "0001":return "1";break;
   case "0010":return "2";break;
   case "0011":return "3";break;
   case "0100":return "4";break;
   case "0101":return "5";break;
   case "0110":return "6";break;
   case "0111":return "7";break;
   case "1000":return "8";break;
   case "1001":return "9";break;
   case "1010":return "A";break;
   case "1011":return "B";break;
   case "1100":return "C";break;
   case "1101":return "D";break;
   case "1110":return "E";break;
   case "1111":return "F";break;
   default:return "";break;
  }
 }else{
  switch(v.toString()){
   case "0":return "0000";break;
   case "1":return "0001";break;
   case "2":return "0010";break;
   case "3":return "0011";break;
   case "4":return "0100";break;
   case "5":return "0101";break;
   case "6":return "0110";break;
   case "7":return "0111";break;
   case "8":return "1000";break;
   case "9":return "1001";break;
   case "A":return "1010";break;
   case "B":return "1101";break;
   case "C":return "1100";break;
   case "D":return "1101";break;
   case "E":return "1110";break;
   case "F":return "1111";break;
   default:return "";break;
  }
 }
}
//------ 结束 ------

//二进制 --> 十六进制
function tw2stChange(n,tp){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = "";
 if(tp=="intType"){
  for(var i=ln;i>0;i -= 4){
   var tempN = strN.substring(i-4,i);
   if(tempN.length<4){
    tempN = dhString((4-tempN.length),"0")+tempN;
   }
   tempInt = twMatchst(tempN,16)+tempInt;
  }
 }else{
  for(var i=0;i<ln;i += 4){
   var tempN = strN.substring(i,i+4);
   if(tempN.length<4){
    tempN = tempN+dhString((4-tempN.length),"0");
   }
   tempInt += twMatchst(tempN,16);
  }
 }
 return tempInt;
}

function tw2st(n){
 var strN = n.toString();
 var tempInt = 0;
 var ln = strN.length;
 var ld = strN.indexOf(".")
 if(ld<0){
  tempInt = tw2stChange(strN,"intType");
 }else{
  var ti = strN.substring(0,ld);
  var tm = strN.substring(ld+1,ln);
  var tempInt1 = tw2stChange(ti,"intType");
  var tempInt2 = tw2stChange(tm,"modType");
  tempInt = tempInt1+"."+tempInt2;
 }
 return tempInt;
}
//------ 结束 ------
var e = "110110111.101001";
document.write(e+" --2T16--> "+tw2st(e)+"<br>");

//十六进制 --> 二进制
function st2twChange(n){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = "";
 for(var i=0;i<ln;i++){
  var t = strN.substr(i,1);
  var e = ln-i-1;
  tempInt += twMatchst(t,2);
 }
 return tempInt;
}

function st2tw(n){
 var strN = n.toString();
 var tempInt = 0;
 var ln = strN.length;
 var ld = strN.indexOf(".")
 if(ld<0){
  tempInt = st2twChange(strN);
 }else{
  var ti = strN.substring(0,ld);
  var tm = strN.substring(ld+1,ln);
  var tempInt1 = st2twChange(ti);
  var tempInt2 = st2twChange(tm);
  tempInt = tempInt1+"."+tempInt2;
 }
 return tempInt;
}
//------ 结束 ------
var f = "1B7.A4";
document.write(f+" --16T2--> "+st2tw(f)+"<br>");
document.write("<br>八进制、十进制转换<hr>");

//八进制 --> 十进制
function ei2teChange(n){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = 0;
 for(var i=0;i<ln;i++){
  var t = strN.substr(i,1);
  var e = ln-i-1;
  if(!isNaN(t)){
   tempInt += t*(Math.pow(8,e));
  }else{
   tempInt += "?";
  }
 }
 return tempInt;
}
function ei2te(n){
 var strN = n.toString();
 var tempInt = 0;
 var ln = strN.length;
 var ld = strN.indexOf(".")
 if(ld<0){
  tempInt = ei2teChange(strN);
 }else{
  var ti = strN.substring(0,ld);
  var tm = strN.substring(ld+1,ln);
  var tempInt1 = ei2teChange(ti);
  var tempInt2 = ei2teChange(tm);
  tempInt = tempInt1+"."+tempInt2;
 }
 return tempInt;
}
//------ 结束 -----
var g = "267.54";
document.write(g+" --8T10--> "+ei2te(g)+"<br>");

//十进制 --> 八进制
function te2eiChange(n){
 if(!isNaN(n) && n>0){
  if(n%8==0){
   return te2eiChange(n/8)+"0";
  }else{
   if(n>8){
    return te2eiChange(parseInt(n/8))+(n%8);
   }else{
    return te2eiChange(0)+n;
   }
  }
 }else{
  return "";
 }
}

function te2ei(n){
 if(!isNaN(n)){
  var strN = n.toString();
  var tempInt = 0;
  var ln = strN.length;
  var ld = strN.indexOf(".")
  if(ld<0){
   tempInt = te2eiChange(n);
  }else{
   var ti = strN.substring(0,ld);
   var tm = strN.substring(ld+1,ln);
   var tempInt1 = te2eiChange(ti);
   var tempInt2 = te2eiChange(tm);
   tempInt = tempInt1+"."+tempInt2;
  }
  return tempInt;
 }else{
  return "false";
 }
}
//------ 结束 -----
var h = 183.44;
document.write(h+" --10T8--> "+te2ei(h)+"<br>");
document.write("<br>十六进制、十进制转换<hr>");

//十进制 <-匹配表-> 十六进制
function teMatchst(v,rv){
 if(rv==16){
  switch(v.toString()){
   case "0":return "0";break;
   case "1":return "1";break;
   case "2":return "2";break;
   case "3":return "3";break;
   case "4":return "4";break;
   case "5":return "5";break;
   case "6":return "6";break;
   case "7":return "7";break;
   case "8":return "8";break;
   case "9":return "9";break;
   case "10":return "A";break;
   case "11":return "B";break;
   case "12":return "C";break;
   case "13":return "D";break;
   case "14":return "E";break;
   case "15":return "F";break;
   default:return "";break;
  }
 }else{
  switch(v.toString()){
   case "0":return "0";break;
   case "1":return "1";break;
   case "2":return "2";break;
   case "3":return "3";break;
   case "4":return "4";break;
   case "5":return "5";break;
   case "6":return "6";break;
   case "7":return "7";break;
   case "8":return "8";break;
   case "9":return "9";break;
   case "A":return "10";break;
   case "B":return "11";break;
   case "C":return "12";break;
   case "D":return "13";break;
   case "E":return "14";break;
   case "F":return "15";break;
   default:return "";break;
  }
 }
}
//------ 结束 ------

//十六进制 --> 十进制
function st2teChange(n){
 var strN = n.toString();
 var ln = strN.length;
 var tempInt = 0;
 for(var i=0;i<ln;i++){
  var t = strN.substr(i,1);
  t = teMatchst(t,10)
  var e = ln-i-1;
  if(!isNaN(t)){
   tempInt += t*(Math.pow(16,e));
  }else{
   tempInt += "?";
  }
 }
 return tempInt;
}
function st2te(n){
 var strN = n.toString();
 var tempInt = 0;
 var ln = strN.length;
 var ld = strN.indexOf(".")
 if(ld<0){
  tempInt = st2teChange(strN);
 }else{
  var ti = strN.substring(0,ld);
  var tm = strN.substring(ld+1,ln);
  var tempInt1 = st2teChange(ti);
  var tempInt2 = st2teChange(tm);
  tempInt = tempInt1+"."+tempInt2;
 }
 return tempInt;
}
//------ 结束 -----
var i = "A4B7";
document.write(i+" --16T10--> "+st2te(i)+"<br>");

//十进制 --> 十六进制
function te2stChange(n){
 if(!isNaN(n) && n>0){
  if(n%16==0){
   return te2stChange(n/16)+"0";
  }else{
   if(n>16){
    return te2stChange(parseInt(n/16))+teMatchst((n%16),16);
   }else{
    return te2stChange(0)+teMatchst(n,16);
   }
  }
 }else{
  return "";
 }
}

function te2st(n){
 if(!isNaN(n)){
  var strN = n.toString();
  var tempInt = 0;
  var ln = strN.length;
  var ld = strN.indexOf(".")
  if(ld<0){
   tempInt = te2stChange(n);
  }else{
   var ti = strN.substring(0,ld);
   var tm = strN.substring(ld+1,ln);
   var tempInt1 = te2stChange(ti);
   var tempInt2 = te2stChange(tm);
   tempInt = tempInt1+"."+tempInt2;
  }
  return tempInt;
 }else{
  return "false";
 }
}
//------ 结束 -----
var j = 120;
document.write(j+" --10T16--> "+te2st(j)+"<br>");

</script>