Converting byte array to string in javascript

Question

How do I convert a byte array into a string   I have found these functions that do the reverse   function string2Bin s        var b   new Array        var last   s length       for  var i   0  i  lt  last  i              var d   s charCodeAt i           if  d  lt  128              b i    dec2Bin d           else               var c   s charAt i               alert c     is NOT an ASCII character                b i    -1                      return b     function dec2Bin d        var b            for  var i   0  i  lt  8  i              b    d 2    b          d   Math floor d 2              return b      But how do I get the functions working the other way   Thanks   Shao

User · Answer

This should work   String fromCharCode    array     Or  String fromCodePoint    array

User · Answer

Try the new Text Encoding API    x000D   x000D     create an array view of some valid bytes x000D  let bytesView   new Uint8Array  104  101  108  108  111    x000D   x000D  console log bytesView   x000D   x000D     convert bytes to string x000D     encoding can be specfied  defaults to utf-8 which is ascii  x000D  let str   new TextDecoder   decode bytesView    x000D   x000D  console log str   x000D   x000D     convert string to bytes x000D     encoding can be specfied  defaults to utf-8 which is ascii  x000D  let bytes2   new TextEncoder   encode str   x000D   x000D     look  they re the same  x000D  console log bytes2   x000D  console log bytesView   x000D   x000D   x000D

User · Answer

String to byte array   FooBar  split     map c   gt  c charCodeAt 0     Byte array to string   102  111  111  98  97  114  map c   gt  String fromCharCode c   join

User · Answer

The simplest solution I ve found is  var text   atob byteArray

User · Answer

That string2Bin can be written even more succinctly  and without any loops  to boot   function string2Bin   str         return str split     map  function  val              return val charCodeAt  0

User · Answer

You need to parse each octet back to number  and use that value to get a character  something like this   function bin2String array      var result         for  var i   0  i  lt  array length  i          result    String fromCharCode parseInt array i   2          return result     bin2String   01100110    01101111    01101111         foo      Using your string2Bin function to test  bin2String string2Bin  hello world         hello world     Edit  Yes  your current string2Bin can be written more shortly   function string2Bin str      var result         for  var i   0  i  lt  str length  i          result push str charCodeAt i  toString 2          return result      But by looking at the documentation you linked  I think that the setBytesParameter method expects that the blob array contains the decimal numbers  not a bit string  so you could write something like this   function string2Bin str      var result         for  var i   0  i  lt  str length  i          result push str charCodeAt i          return result     function bin2String array      return String fromCharCode apply String  array      string2Bin  foo        102  111  111  bin2String string2Bin  foo         foo      true

User · Answer

Didn t find any solution that would work with UTF-8 characters  String fromCharCode is good until you meet 2 byte character   For example H  ser will come as  0x44 0x61 0x6e 0x69 0x65 0x6c 0x61 0x20 0x48 0xc3 0xbc 0x73 0x65 0x72   But if you go through it with String fromCharCode you will have H    ser as each byte will be converted to a char separately   Solution  Currently I m using following solution    function pad n    return  n length  lt  2    0    n   n     function decodeUtf8 data      return decodeURIComponent      data map byte   gt         pad byte toString 16     join

User · Answer

Too late to answer but if your input is in form of ASCII bytes  then you could try this solution   function convertArrToString rArr      Step 1  Convert each element to character  let tmpArr   new Array     rArr forEach function element index       tmpArr push String fromCharCode element          Step 2  Return the string by joining the elements return tmpArr join          function convertArrToHexNumber rArr     return parseInt convertArrToString rArr  16

User · Answer

I had some decrypted byte arrays with padding characters and other stuff I didn t need  so I did this  probably not perfect  but it works for my limited use   var junk   String fromCharCode apply null  res  split     map char   gt  char charCodeAt 0   lt   127  amp  amp  char charCodeAt 0   gt   32   char       join

User · Answer

I think this would be more efficient   function toBinString  arr        var uarr   new Uint8Array arr map function x  return parseInt x 2          var strings       chunksize   0xffff         There is a maximum stack size  We cannot call String fromCharCode with as many arguments as we want     for  var i 0  i chunksize  lt  uarr length  i             strings push String fromCharCode apply null  uarr subarray i chunksize   i 1  chunksize               return strings join

User · Answer

Even if I m a bit late  I thought it would be interesting for future users to share some one-liners implementations I did using ES6   One thing that I consider important depending on your environment or and what you will do with with the data is to preserve the full byte value  For example   5  toString 2  will give you 101  but the complete binary conversion is in reality 00000101  and that s why you might need to create a leftPad implementation to fill the string byte with leading zeros  But you may not need it at all  like other answers demonstrated   If you run the below code snippet  you ll see the first output being the conversion of the abc string to a byte array and right after that the re-transformation of said array to it s corresponding string    x000D   x000D     For each byte in our array  retrieve the char code value of the binary value x000D  const binArrayToString   array   gt  array map byte   gt  String fromCharCode parseInt byte  2    join     x000D   x000D     Basic left pad implementation to ensure string is on 8 bits x000D  const leftPad   str   gt  str length  lt  8    Array 8  join  0     str  slice -8    str x000D   x000D     For each char of the string  get the int code and convert it to binary  Ensure 8 bits  x000D  const stringToBinArray   str   gt  str split     map c   gt  leftPad c charCodeAt   toString 2    x000D   x000D  const array   stringToBinArray  abc   x000D   x000D  console log array  x000D  console log binArrayToString array   x000D   x000D   x000D

User · Answer

If you are using node js you can do this    yourByteArray toString  base64

User · Answer

If your array is encoded in UTF-8 and you can t use the TextDecoder API because it is not supported on IE    You can use the FastestSmallestTextEncoderDecoder polyfill recommended by the Mozilla Developer Network website  You can use this function also provided at the MDN website     x000D   x000D  function utf8ArrayToString aBytes    x000D      var sView       x000D       x000D      for  var nPart  nLen   aBytes length  nIdx   0  nIdx  lt  nLen  nIdx      x000D          nPart   aBytes nIdx   x000D           x000D          sView    String fromCharCode  x000D              nPart  gt  251  amp  amp  nPart  lt  254  amp  amp  nIdx   5  lt  nLen      six bytes    x000D                      nPart - 252  lt  lt  30  may be not so safe in ECMAScript  So        x000D                   nPart - 252    1073741824    aBytes   nIdx  - 128  lt  lt  24     aBytes   nIdx  - 128  lt  lt  18     aBytes   nIdx  - 128  lt  lt  12     aBytes   nIdx  - 128  lt  lt  6    aBytes   nIdx  - 128 x000D                nPart  gt  247  amp  amp  nPart  lt  252  amp  amp  nIdx   4  lt  nLen      five bytes    x000D                   nPart - 248  lt  lt  24     aBytes   nIdx  - 128  lt  lt  18     aBytes   nIdx  - 128  lt  lt  12     aBytes   nIdx  - 128  lt  lt  6    aBytes   nIdx  - 128 x000D                nPart  gt  239  amp  amp  nPart  lt  248  amp  amp  nIdx   3  lt  nLen      four bytes    x000D                   nPart - 240  lt  lt  18     aBytes   nIdx  - 128  lt  lt  12     aBytes   nIdx  - 128  lt  lt  6    aBytes   nIdx  - 128 x000D                nPart  gt  223  amp  amp  nPart  lt  240  amp  amp  nIdx   2  lt  nLen      three bytes    x000D                   nPart - 224  lt  lt  12     aBytes   nIdx  - 128  lt  lt  6    aBytes   nIdx  - 128 x000D                nPart  gt  191  amp  amp  nPart  lt  224  amp  amp  nIdx   1  lt  nLen      two bytes    x000D                   nPart - 192  lt  lt  6    aBytes   nIdx  - 128 x000D                   nPart  lt  127         one byte    x000D                  nPart x000D             x000D        x000D       x000D      return sView  x000D    x000D   x000D  let str   utf8ArrayToString  50 72 226 130 130 32 43 32 79 226 130 130 32 226 135 140 32 50 72 226 130 130 79    x000D   x000D     Must show 2H2   O2   2H2O x000D  console log str   x000D   x000D   x000D

User · Answer

Simply apply your byte array to String fromCharCode  For example  String fromCharCode apply null   102  111  111    equals  foo     Caveat  works for arrays shorter than 65535   MDN docs here

[javascript] Converting byte array to string in javascript

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