Convert to and from a binary sequence

sequence-as2.as

function str2seq(str:String):String {
    var seq:String = "", byte:String, len:Number = str.length, i:Number = 0;
    for (; i<len; i++) {
        byte = parseInt(ord(str.charAt(i)), 10).toString(2);
        seq += "00000000".substr(0, 8-byte.length) + byte;
    }
    return seq;
}

function seq2str(seq:String):String {    
    var str:String = "", len:Number = seq.length, i:Number = 0;
    for (0; i<len; i+=8) {    
        str += chr(parseInt(seq.substr(i, 8), 2));
    }
    return str;
}

sequence-as3.as

function str2seq(str:String):String {
    var seq:String = "", byte:String, len:Number = str.length, i:Number = 0;
    for (; i<len; i++) {
        byte = (str.charCodeAt(i)).toString(2);
        seq += "00000000".substr(0, 8-byte.length) + byte;
    }
    return seq;
}

function seq2str(seq:String):String {    
    var str:String = "", len:Number = seq.length, i:Number = 0;
    for (0; i<len; i+=8) {    
        str += String.fromCharCode(parseInt(seq.substr(i, 8), 2));
    }
    return str;
}

sequence.js

function str2seq(str) {
  var seq = '', byte, len = str.length, i = 0;
  for (; i<len; i++) {
    byte = (str.charCodeAt(i)).toString(2);
    seq += '00000000'.substr(0, 8-byte.length) + byte;
  }
  return seq;
}

function seq2str(seq) {  
  var str = '', len = seq.length, i = 0;
  for (0; i<len; i+=8) {  
    str += String.fromCharCode(parseInt(seq.substr(i, 8), 2));
  }
  return str;
}

sequence.php

<?php

  function str2seq($str) {
    $seq = '';
    for($i=0; $i<strlen($str); $i++){
      $byte = decbin(ord($str[$i]));
      $seq .= substr('00000000', 0, 8-strlen($byte)) . $byte;
    }
    return $seq;      
  }
  
  function seq2str($seq) {
    if (strlen($seq) % 8 != 0) {
      return NULL;
    }
    $str = '';
    for($i=0; $i<strlen($seq); $i+=8) {
      $str .= chr(bindec(substr($seq, $i, 8)));
    }
    return $str;
  }

?>