JS: How to convert an Array-like list of character numbers to a string

binstr-cmp.js

/*jslint indent: 2, maxlen: 80, browser: true */
/* -*- tab-width: 2 -*- */
'use strict';

var bytes, s1, s2, arSlc = Array.prototype.slice;

// Let's assume the worst minimalistic buffer API ever imagined:
bytes = { length: 15,
  '0': 72, '1': 101, '2': 108, '3': 108, '4': 111, '5': 32,
  '6': 119, '7': 111, '8': 114, '9': 108, '10': 100, '11': 33,
  '12': 32, '13': 9749, '14': 9774 };


function dare(func, arg) {
  try {
    return func(arg);
  } catch (err) {
    return 'E: ' + String(err.message || err);
  }
}


// version from https://github.com/Daplie/unibabel-js/blob/master/index.js#L50
// License: Apache-2.0, https://opensource.org/licenses/Apache-2.0
function bufferToBinaryString(buf) {
  var binstr = Array.prototype.map.call(buf, function (ch) {
    return String.fromCharCode(ch);
  }).join('');

  return binstr;
}
s1 = dare(bufferToBinaryString, bytes);

// intuitive version:
function easyInFirefox(buf) { return String.fromCharCode.apply(null, buf); }

// MSIE 6 compatibility version:
function buf2binstr(buf) {
  return String.fromCharCode.apply(null,
    // If you target modern browsers, replace the next line with just "buf".
    arSlc.call(buf)
    // The array conversion wastes CPU in Node.js and Firefox since they
    // can .apply() the original buf directly. However, if you try that
    // in MSIE 6 it throws an Error("Array or arguments object expected")
    );
}
s2 = dare(buf2binstr, bytes);

if ((typeof window === 'object') && (!window.console)) {
  window.console = { log: function (arr) {
    document.getElementsByTagName('body')[0].innerHTML = '<pre>' +
      arr.join(' | ') + '</pre>\n';
  } };
}

console.log([ s1, s2, (s1 === s2) ]);
// Output in Node.js v6.11.0 and Firefox v53.0:
// [ 'Hello world! ☕☮', 'Hello world! ☕☮', true ]
// Output in MSIE v6:
// E: 'Array.prototype.map' is null or not an object | Hello world! ☕☮ | false