【JavaScript】js实现十六进制与浮点数的转换

时间：2024-03-04 16:44:24

来自ampedZ的博客园，原文地址：http://www.cnblogs.com/ampedZ/p/HexToSingle.html

基于IEEE 745标准的Hex与Single的转换，并加入了一定的防错处理。

<!DOCTYPE html>
<html><head><style type="text/css">
div#divBase{text-align:center;width:283px;}
div#divTitle{clear:both;text-align:center;padding:3px;}
div#divInput{float:left;}
div#divOutput{float:right;}
div#divButton{float:none;vertical-align:middle;margin:36px;}
div#divCopyright{clear:both;text-align:center;padding:3px;}
textarea#textareaInput{resize:none;overflow:auto;width:106px;height:126px;}
textarea#textareaOutput{resize:none;overflow:auto;width:106px;height:126px;}</style></head>
<body><div id="divBase">
<div id="divTitle">十六进制浮点数转换</div>
<div id="divInput"><textarea id="textareaInput"wrap="soft">42 0C 00 00
42 82 00 00</textarea></div>
<div id="divOutput"><textarea id="textareaOutput"wrap="soft">35
65</textarea></div>
<div id="divButton"><input type="button"value="　＝》"onClick="ConvertToSingle()"/><input type="button"value="《＝　"onClick="ConvertToHex()"/></div>
<div id="divCopyright">Copyright © 心のsky Group</div></div>
<script type="text/javascript"src="HexToSingle.js"></script>
<script type="text/javascript">function ConvertToSingle()
{var t=document.getElementById("textareaInput").value;t=HexToSingleBatch(t);document.getElementById("textareaOutput").value=t;}
function ConvertToHex()
{var t=document.getElementById("textareaOutput").value;t=SingleToHexBatch(t);document.getElementById("textareaInput").value=t;}</script>
</body></html>
HexToSingle.html
function InsertString(t, c, n) {
    var r = new Array();
    for (var i = 0; i * 2 < t.length; i++) {
        r.push(t.substr(i * 2, n));
    }
    return r.join(c);
}
function FillString(t, c, n, b) {
    if ((t == "") || (c.length != 1) || (n <= t.length)) {
        return t;
    }
    var l = t.length;
    for (var i = 0; i < n - l; i++) {
        if (b == true) {
            t = c + t;
        }
         else {
            t += c;
        }
    }
    return t;
}
function HexToSingle(t) {
    t = t.replace(/\s+/g, "");
    if (t == "") {
        return "";
    }
    if (t == "00000000") {
        return "0";
    }
    if ((t.length > 8) || (isNaN(parseInt(t, 16)))) {
        return "Error";
    }
    if (t.length < 8) {
        t = FillString(t, "0", 8, true);
    }
    t = parseInt(t, 16).toString(2);
    t = FillString(t, "0", 32, true);
    var s = t.substring(0, 1);
    var e = t.substring(1, 9);
    var m = t.substring(9);
    e = parseInt(e, 2) - 127;
    m = "1" + m;
    if (e >= 0) {
        m = m.substr(0, e + 1) + "." + m.substring(e + 1)
    }
     else {
        m = "0." + FillString(m, "0", m.length - e - 1, true)
    }
    if (m.indexOf(".") == -1) {
        m = m + ".0";
    }
    var a = m.split(".");
    var mi = parseInt(a[0], 2);
    var mf = 0;
    for (var i = 0; i < a[1].length; i++) {
        mf += parseFloat(a[1].charAt(i)) * Math.pow(2, -(i + 1));
    }
    m = parseInt(mi) + parseFloat(mf);
    if (s == 1) {
        m = 0 - m;
    }
    return m;
}
function SingleToHex(t) {
    if (t == "") {
        return "";
    }
    t = parseFloat(t);
    if (isNaN(t) == true) {
        return "Error";
    }
    if (t == 0) {
        return "00000000";
    }
    var s,
    e,
    m;
    if (t > 0) {
        s = 0;
    }
     else {
        s = 1;
        t = 0 - t;
    }
    m = t.toString(2);
    if (m >= 1) {
        if (m.indexOf(".") == -1) {
            m = m + ".0";
        }
        e = m.indexOf(".") - 1;
    }
     else {
        e = 1 - m.indexOf("1");
    }
    if (e >= 0) {
        m = m.replace(".", "");
    }
     else {
        m = m.substring(m.indexOf("1"));
    }
    if (m.length > 24) {
        m = m.substr(0, 24);
    }
     else {
        m = FillString(m, "0", 24, false)
    }
    m = m.substring(1);
    e = (e + 127).toString(2);
    e = FillString(e, "0", 8, true);
    var r = parseInt(s + e + m, 2).toString(16);
    r = FillString(r, "0", 8, true);
    return InsertString(r, " ", 2).toUpperCase();
}
function FormatHex(t, n, ie) {
    var r = new Array();
    var s = "";
    var c = 0;
    for (var i = 0; i < t.length; i++) {
        if (t.charAt(i) != " ") {
            s += t.charAt(i);
            c += 1;
            if (c == n) {
                r.push(s);
                s = "";
                c = 0;
            }
        }
        if (ie == false) {
            if ((i == t.length - 1) && (s != "")) {
                r.push(s);
            }
        }
    }
    return r.join("\n");
}
function FormatHexBatch(t, n, ie) {
    var a = t.split("\n");
    var r = new Array();
    for (var i = 0; i < a.length; i++) {
        r[i] = FormatHex(a[i], n, ie);
    }
    return r.join("\n");
}
function HexToSingleBatch(t) {
    var a = FormatHexBatch(t, 8, true).split("\n");
    var r = new Array();
    for (var i = 0; i < a.length; i++) {
        r[i] = HexToSingle(a[i]);
    }
    return r.join("\r\n");
}
function SingleToHexBatch(t) {
    var a = t.split("\n");
    var r = new Array();
    for (var i = 0; i < a.length; i++) {
        r[i] = SingleToHex(a[i]);
    }
    return r.join("\r\n");
}
HexToSingle.js

 

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