假设我在 JavaScript 中有一个字符串，其中包含二进制数据。它可能看起来像这样：
var binary = '00001000010001000101010100001110';
我需要一些可靠的函数将其转换为十六进制字符串，然后再次从该十六进制转换回二进制字符串。我知道以下功能
// Convert binary to hexadecimal
var hex = parseInt(binaryCharacters, 2).toString(16);
// Convert hexadecimal to binary
var binary = parseInt(hex, 16).toString(2)
但我不确定如何一次转换整个字符串。我是否理解我需要一次将每 4 个二进制位转换为一个十六进制字符？然后回到二进制我遍历每个十六进制字符并再次转换为二进制？
我一直在寻找一些在 JavaScript 中执行此操作的简单示例，但找不到任何示例。
非常感谢
对您来说更有趣的功能在这里。不一定是最干净或最有效的，但是是的：
// converts binary string to a hexadecimal string
// returns an object with key 'valid' to a boolean value, indicating
// if the string is a valid binary string.
// If 'valid' is true, the converted hex string can be obtained by
// the 'result' key of the returned object
function binaryToHex(s) {
var i, k, part, accum, ret = '';
for (i = s.length-1; i >= 3; i -= 4) {
// extract out in substrings of 4 and convert to hex
part = s.substr(i+1-4, 4);
accum = 0;
for (k = 0; k < 4; k += 1) {
if (part[k] !== '0' && part[k] !== '1') {
// invalid character
return { valid: false };
}
// compute the length 4 substring
accum = accum * 2 + parseInt(part[k], 10);
}
if (accum >= 10) {
// 'A' to 'F'
ret = String.fromCharCode(accum - 10 + 'A'.charCodeAt(0)) + ret;
} else {
// '0' to '9'
ret = String(accum) + ret;
}
}
// remaining characters, i = 0, 1, or 2
if (i >= 0) {
accum = 0;
// convert from front
for (k = 0; k <= i; k += 1) {
if (s[k] !== '0' && s[k] !== '1') {
return { valid: false };
}
accum = accum * 2 + parseInt(s[k], 10);
}
// 3 bits, value cannot exceed 2^3 - 1 = 7, just convert
ret = String(accum) + ret;
}
return { valid: true, result: ret };
}
// converts hexadecimal string to a binary string
// returns an object with key 'valid' to a boolean value, indicating
// if the string is a valid hexadecimal string.
// If 'valid' is true, the converted binary string can be obtained by
// the 'result' key of the returned object
function hexToBinary(s) {
var i, k, part, ret = '';
// lookup table for easier conversion. '0' characters are padded for '1' to '7'
var lookupTable = {
'0': '0000', '1': '0001', '2': '0010', '3': '0011', '4': '0100',
'5': '0101', '6': '0110', '7': '0111', '8': '1000', '9': '1001',
'a': '1010', 'b': '1011', 'c': '1100', 'd': '1101',
'e': '1110', 'f': '1111',
'A': '1010', 'B': '1011', 'C': '1100', 'D': '1101',
'E': '1110', 'F': '1111'
};
for (i = 0; i < s.length; i += 1) {
if (lookupTable.hasOwnProperty(s[i])) {
ret += lookupTable[s[i]];
} else {
return { valid: false };
}
}
return { valid: true, result: ret };
}
为什么不使用Array.prototype.reduce？
var binstr = "00001000010001000101010100001110"
function bin2hex(b) {
return b.match(/.{4}/g).reduce(function(acc, i) {
return acc + parseInt(i, 2).toString(16);
}, '')
}
function hex2bin(h) {
return h.split('').reduce(function(acc, i) {
return acc + ('000' + parseInt(i, 16).toString(2)).substr(-4, 4);
}, '')
}
console.log(binstr);
> 00001000010001000101010100001110
console.log(bin2hex(binstr));
> 0844550e
console.log(hex2bin(bin2hex(binstr)));
> 00001000010001000101010100001110
在这里链接到 jsfiddle 。
笔记：
bin2hex中，如果您还想将小于 4 位的尾随块转换为十六进制，请替换{4}为{1,4}. 但是，将结果转换回二进制会产生与原始字符串不同的字符串。例如，来回转换"111101"会产生"11110001".hex2bin中，二进制值用零填充，以便每个十六进制数字有 4 个二进制数字。好吧，我在这里找到了一个有助于解释如何做到这一点的算法。维基百科上的这个页面也帮助确认了 4 位二进制到十六进制的映射。我想出了以下代码来做到这一点。我在网上找到的其他代码片段根本不起作用。让我知道您是否会做出任何改进。您甚至可以直接使用来自维基百科的信息进行直接查找表，这样会更快。
var tools = {
/**
* Converts binary code to hexadecimal string
* @param {string} binaryString A string containing binary numbers e.g. '01001101'
* @return {string} A string containing the hexadecimal numbers
*/
convertBinaryToHexadecimal: function(binaryString)
{
var output = '';
// For every 4 bits in the binary string
for (var i=0; i < binaryString.length; i+=4)
{
// Grab a chunk of 4 bits
var bytes = binaryString.substr(i, 4);
// Convert to decimal then hexadecimal
var decimal = parseInt(bytes, 2);
var hex = decimal.toString(16);
// Uppercase all the letters and append to output
output += hex.toUpperCase();
}
return output;
},
/**
* Converts hexadecimal code to binary code
* @param {string} A string containing single digit hexadecimal numbers
* @return {string} A string containing binary numbers
*/
convertHexadecimalToBinary: function(hexString)
{
var output = '';
// For each hexadecimal character
for (var i=0; i < hexString.length; i++)
{
// Convert to decimal
var decimal = parseInt(hexString.charAt(i), 16);
// Convert to binary and add 0s onto the left as necessary to make up to 4 bits
var binary = this.leftPadding(decimal.toString(2), '0', 4);
// Append to string
output += binary;
}
return output;
},
/**
* Left pad a string with a certain character to a total number of characters
* @param {string} inputString The string to be padded
* @param {string} padCharacter The character that the string should be padded with
* @param {string} totalCharacters The length of string that's required
* @returns {string} A string with characters appended to the front of it
*/
leftPadding: function(inputString, padCharacter, totalCharacters)
{
// If the string is already the right length, just return it
if (!inputString || !padCharacter || inputString.length >= totalCharacters)
{
return inputString;
}
// Work out how many extra characters we need to add to the string
var charsToAdd = (totalCharacters - inputString.length)/padCharacter.length;
// Add padding onto the string
for (var i = 0; i < charsToAdd; i++)
{
inputString = padCharacter + inputString;
}
return inputString;
}
};
要将 bin 转换为十六进制和反向，我使用以下函数：
function bintohex()
{
mybin = document.getElementById('bin').value;
z = -1; number = 0;
for(i = mybin.length; i > -1; i--)
{
//Every 1 in binary string is converted to decimal and added to number
if(mybin.charAt(i) == "1"){
number += Math.pow(2, z);
}
z+=1;
}
// Return is converting decimal to hexadecimal
document.getElementById('result').innerHTML = number.toString(16);
}
function hextobin()
{
mybin = "";
/// Converting to decimal value and geting ceil of decimal sqrt
myhex = document.getElementById('hex').value;
mydec = parseInt(myhex, 16);
i = Math.ceil( Math.sqrt(mydec) );
while(i >= 0)
{
if(Math.pow(2, i) <= mydec){
mydec = mydec-Math.pow(2, i);
mybin += "1";
}else if(mybin != "")
mybin = mybin + "0";
i = i-1;
}
document.getElementById('result').innerHTML = mybin;
}Input binary: <input type = "text" id = "bin">
<button onclick = "bintohex()">Convert to Hex</button><br />
Input Hecadecimal: <input type = "text" id = "hex">
<button onclick = "hextobin()">Convert to Bin</button><br />
Results: <div id = "result"></div>不要忘记检查您的答案。