How to remove 'Object has no method 'forEach' error in node.js'?

Question

My code is as follows:-

var generateTypos = function(keywords, options) {
 // Adding a function to the String Prototype that allows to
// change characters at a certain index.
// Needed, since "string"[n] is read-only
String.prototype.replaceAt=function(index, char) {
return this.substr(0, index) + char + this.substr(index+char.length);
};
// Basically a JS Implementation of
// http://web-professor.net/scripts/typo/cTypoGenerator.txt
var keyboard = {"1":["2","q"],"2":["1","q","w","3"],"3":["2","w","e","4"],"4":  ["3","e","r","5"],"5":["4","r","t","6"],"6":["5","t","y","7"],"7":["6","y","u","8"],"8":["7","u","i","9"],"9":["8","i","o","0"],"0":["9","o","p","-"],"-":["0","p"],"q":["1","2","w","a"],"w":["q","a","s","e","3","2"],"e":["w","s","d","r","4","3"],"r":["e","d","f","t","5","4"],"t":["r","f","g","y","6","5"],"y":["t","g","h","u","7","6"],"u":["y","h","j","i","8","7"],"i":["u","j","k","o","9","8"],"o":["i","k","l","p","0","9"],"p":["o","l","-","0"],"a":["z","s","w","q"],"s":["a","z","x","d","e","w"],"d":["s","x","c","f","r","e"],"f":["d","c","v","g","t","r"],"g":["f","v","b","h","y","t"],"h":["g","b","n","j","u","y"],"j":["h","n","m","k","i","u"],"k":["j","m","l","o","i"],"l":["k","p","o"],"z":["x","s","a"],"x":["z","c","d","s"],"c":["x","v","f","d"],"v":["c","b","g","f"],"b":["v","n","h","g"],"n":["b","m","j","h"],"m":["n","k","j"]},
typos = [];
// Generate a homophone object
function getHomophones() {
// German + English Homophones
var homophones = ["Aale, Ahle","Ai, Ei","Annalen, analen","aß, Aas","Bad, bat","bald, ballt","Bällen, bellen","Band, bannt","Beete, bete","bis, Biss","Block, Blog","Boot, bot","Boote, Bote","Bug, buk","Bund, bunt","Chor, Korps","Code, Kot","das, dass","dehnen, denen","erhält, erhellt","Fähre, faire","Fälle, Felle","fällt, Feld","Färse, Ferse, Verse","fast, fasst","fetter, Vetter","fiel, viel","fließt, fliehst, fliest","frisst, Frist","Fühler, Phyla","Geld, gellt","Gewand, gewandt","Grad, Grat","Graf, Graph","Halt, hallt","hallte, halte","hält, Held, hellt","Hämmer, Hemmer","hängst, Hengst","harrt, hart","hasst, hast","Häute, heute","Heer, hehr, her","Hemd, hemmt","hohl, hol","Hund, Hunt","isst, ist","kannte, Kante","konnten, Konten","Kuh, Coup","küsste, Küste","Laib, Leib","Laie, Leihe","laichen, Leichen","lasst, Last","läuten, Leuten","Lärche, Lerche","Leere, Lehre","leeren, lehren","Leerstelle, Lehrstelle","Leid, leiht","Lid, Lied","lies, ließ","liest, least","Mahl, Mal","Mähre, Märe, Meere","mahlen, malen","man, Mann","Märkte, merkte","Meer, mehr","Miene, Mine","misst, Mist","Mohr, Moor","mühten, Mythen","Mund, Munt","Nachnahme, Nachname","nahmen, Namen","packt, Pakt","pisste, Piste","rächen, Rechen","rächt, Recht","Rad, Rat","Rain, rein","Rede, Reede","Reis, reiß","reist, reißt","ruhte, Rute, Route","säen, sähen","Sämann, Seemann","Sätzen, setzen","Saite, Seite","seid, seit","schafft, Schaft","schallten, schalten","Schänke, schenke","schellte, Schelte","Schlächter, schlechter","Schlämme, schlemme","Schwälle, Schwelle","Schwämme, Schwemme","Seen, sehen","seid, seiht, seit","sie, sieh","Siegel, Sigel","Sohle, Sole","Sold, sollt","späht, spät","Stadt, statt","Städte, Stätte","Ställe, Stelle","starrt, Start","stehlen, Stelen","stiehl, Stiel, Stil","Tod, tot","Trend, trennt","Uhrzeit, Urzeit","Verband, verbannt","Verben, werben","verließ, Verlies","verwaist, verweist","Villen, Willen","Waage, vage","Waagen, wagen","Wahl, Wal","wahr, war","wahre, Ware","Waise, Weise","Wald, wallt","Wälle, Welle","Wände, Wende","Weck, weg","Wehr, wer","wehrt, Wert","weiht, weit","weis, weiß","weist, weißt","wieder, wider","wird, Wirt","Zunahme, Zuname","accept,except","acclamation,acclimation","acts,ax,axe","adolescence,adolescents","aeration,erration","aerie,airy","affect,effect","aid,aide","ail,ale","air,heir,err,ere","aisle,isle,I'll","all,awl","allowed,aloud","allude,elude","altar,alter","appose,oppose","arc,ark","are,our","ascent,assent","ate,eight","away,aweigh","aye,I,eye","bade,bayed","bail,bale","bait,bate","bald,bawled,balled","ball,bawl","band,banned","bard,barred","bare,bear","baron,barren","base,bass","based,baste","bazaar,bizarre","be,bee","beach,beech","bean,been","beat,beet","been,bin","beer,bier","bell,belle","berry,bury","berth,birth","better,bettor","bight,bite","billed,build","bird,burred","blew,blue","boar,bore,boor","board,bored","boarder,border","bode,bowed","bold,bowled","bolder,boulder,bowlder","bole,bowl","boos,booze","bough,bow","boy,buoy","braid,brayed","braise,braze,brays,braize","brake,break","breach,breech","bread,bred","brewed,brood","brews,bruise","bridal,bridle","burro,burrow","bus,buss","bused,bust","but,butt","buy,bye,by","cache,cash","callous,callus","can't,cant","cannon,canon","canter,cantor","carat,carrot,caret","caries,carries","cast,caste","cede,seed","cell,sell","cellar,seller","censor,sensor","cent,sent,scent","cents,sense,scents","cereal,serial","cession,session","chaise,chase","chalk,chock","chance,chants","chased,chaste","cheap,cheep","chews,choose","chic,sheik","choir,quire","chord,cored,cord","chute,shoot","cite,site,sight","clause,claws","click,clique","close,clothes","coal,cole","coaled,cold","coarse,course","coated,coded","cocks,cox","complement,compliment","contingence,contingents","coo,coup","coop,coupe","correspondence,correspondents","cosign,cosine","council,counsel","councilor,counselor","creak,creek","crewed,crude","crews,cruise","cue,queue","currant,current","curser,cursor","dam,damn","Dane,deign","days,daze","dear,deer","dense,dents","dependence,dependents","dew,due,do","die,dye","dire,dyer","discreet,discrete","doe,dough","does,doze,doughs","done,dun","dual,duel","ducked,duct","earn,urn","either,ether","emigrant,immigrant","eutopia,utopia","ewe,you,yew","eyed,I'd","fain,feign","faint,feint","fair,fare","fairy,ferry","fate,fete","faze,phase","feat,feet","feudal,futile","find,fined","finish,Finnish","fir,fur","flair,flare","flea,flee","flecks,flex","flew,flue","flour,flower","foaled,fold","for,four,fore","forego,forgo","foreword,forward","forth,fourth","foul,fowl","frees,frieze,freeze","friar,fryer","gage,gauge","gait,gate","gel,jell","gene,jean","gild,guild","gneiss,nice","gored,gourd","grade,grayed,greyed","grate,great","grays,greys,graze","grisly,grizzly","groan,grown","guessed,guest","guide,guyed","guise,guys","hail,hale","hair,hare","hairy,harry","hall,haul","halve,have","hangar,hanger","hay,hey","hays,haze","he'd,heed","he'll,heel,heal","hear,here","heard,herd","heated,heeded","hew,hue","hi,high","higher,hire","him,hymn","ho,hoe","hoar,whore","hoard,horde","hoarse,horse","hoes,hose","hold,holed","hole,whole","holey,wholly,holy","hostel,hostile","hour,our","idle,idol","immanent,imminent","in,inn","incidence,incidents","incite,insight","instance,instants","intense,intents","intension,intention","it's,its","jam,jamb","knave,nave","knead,need,kneed","knew,new","knight,night","knit,nit","knot,not,naught","know,no","knows,nose","lacks,lax","lade,laid","lain,lane","lair,layer","lam,lamb","laps,lapse","lay,lei","lays,laze","leach,leech","lead,led","leak,leek","lean,lien","leased,least","lends,lens","lessen,lesson","lesser,lessor","let's,lets","levee,levy","liar,lyre","lichen,liken","lickerish,licorice","lie,lye","links,lynx","lo,low","load,lode","loan,lone","loch,lock","locks,lox","loop,loupe","loos,lose","lose,loose","made,maid","mail,male","main,mane","maize,maze,Mays","mall,maul","manner,manor","marshal,martial","massed,mast","mat,matte","mean,mien","meat,mete,meet","medal,mettle,meddle,metal","might,mite","mince,mints","mind,mined","miner,minor","missed,mist","moat,mote","mood,mooed","moor,more","morning,mourning","muscle,mussel","mussed,must","naval,navel","nay,neigh","nicks,nix","none,nun","oar,ore,or","ode,owed","oh,owe","once,wants","one,won","oohs,ooze","overseas,oversees","paced,paste","packed,pact","pail,pale","pain,pane","pair,pear,pare","palate,pallet,palette","parish,perish","passed,past","patience,patients","pause,paws","peace,piece","peak,pique,peek","peal,peel","pearl,purl","pedal,petal,peddle","peer,pier","penance,pennants","per,purr","pi,pie","plain,plane","plainer,planer,planar","plait,plate","pleas,please","pole,poll","poor,pour,pore","populace,populous","praise,preys,prays","pray,prey","precedence,precedents","premier,premiere","presence,presents","pride,pried","prier,prior","pries,prize","prince,prints","principal,principle","profit,prophet","rack,wrack","raid,rayed","rail,rale","rain,rein,reign","raise,raze,rays","rap,wrap","rapt,wrapped,wrapt","re-cover,recover","re-lay,relay","read,red","read,reed","real,reel","recede,reseed","reek,wreak","residence,residents","rest,wrest","retch,wretch","rhyme,rime","right,write,rite,wright","ring,wring","ringer,wringer","rise,ryes","road,rowed,rode","roe,row","roil,royal","role,roll","roomer,rumor,rumour","root,route","rose,rows","rote,wrote","rude,rued","rues,ruse","rung,wrung","rye,wry","sail,sale","scene,seen","sea,see","seam,seem","sear,seer","seas,seize,sees","sects,sex","sew,sow,so","shake,sheik","shear,sheer","shoe,shoo","sic,sick","sics,six","side,sighed","sighs,size","sign,sine","slay,sleigh","sleight,slight","slew,slough","soar,sore","soared,sword","sold,soled","sole,soul","some,sum","son,sun","stair,stare","stake,steak","steal,steel","step,steppe","storey,story","straight,strait","suite,sweet","tacked,tact","tacks,tax","tail,tale","taper,tapir","tarry,terry","taught,taut","tea,tee","team,teem","tears,tiers","teas,tees,tease","tense,tents","than,then","there,they're,their","threw,through","throne,thrown","thyme,time","tide,tied","tier,tire","tighten,titan","to,two,too","toad,towed,toed","toe,tow","told,tolled","tracked,tract","tray,trey","udder,utter","vain,vein,vane","vale,veil","vial,vile","vice,vise","wade,weighed","wail,whale","waist,waste","wait,weight","waive,wave","waiver,waver","wale,whale","war,wore","ward,warred","ware,where,wear","warn,worn","wax,whacks","way,whey,weigh","we,wee","we'd,weed","we'll,wheel,weal,wheal","we're,weir,were","we're,whir","we've,weave","weak,week","wearer,where're","weather,whether","wet,whet","wheeled,wield","which,witch","while,wile","whiled,wild","whine,wine","whined,wined,wind","whirled,world","whit,wit","whither,wither","who's,whose","whoa,woe","wood,would","yack,yak","yaw,your,yore,you're","yoke,yolk","yore,your,you're","you'll,Yule","aahed,odd","adieu,ado","ant,aunt","aural,oral","marry,merry","rout,route","seated,seeded","shone,shown","tidal,title","trader,traitor","vary and very"];
var word_sets = homophones.map(function(x) {
return x.toLocaleLowerCase().trim().split(',');
}),
dictionary = {};
word_sets.forEach(function(set) {
set.forEach(function(word) {
dictionary[word] = set;
});
});

return dictionary;
}

// Generate wrong key typos
function wrongKeyTypos(word) {
var word = word.toLocaleLowerCase(),
typos = [],
length = word.length;

for(var i = 0; i < length; i++ ) {
if(keyboard[word[i]]) {
var tempWord = word;
keyboard[word[i]].forEach(function(character) {
typos.push(tempWord.replaceAt(i, character).trim());
});
}
}

return typos;
}

// generate missed character typos
function missedCharsTypos(word) {
var word = word.toLocaleLowerCase(),
typos = [],
length = word.length;

for(var i = 0; i < length; i++) {
var tempWord = '';
if(i === 0) {
tempWord = word.substring(i + 1);
}
else if((i + 1) === length) {
tempWord = word.substring(0, i);
}
else {
tempWord = word.substring(0, i);
tempWord += word.substring(i + 1);
}

typos.push(tempWord);

}

return typos;
}

// generate transposed character typos
function transposedCharTypos(word) {
var word = word.toLocaleLowerCase(),
typos = [],
length = word.length;

for(var i = 0; i < length; i++) {
if((i + 1) !== length) {
var tempWord = word,
tempChar = tempWord[i];
tempWord = tempWord.replaceAt(i, tempWord[i + 1]);
tempWord = tempWord.replaceAt((i + 1), tempChar);
typos.push(tempWord);
}
}

return typos;
}

// generate double character typos
  function doubleCharTypos(word) {
  var word = word.toLocaleLowerCase(),
  typos = [],
  length = word.length;

  for(var i = 0; i < length; i++) {
  var tempWord = word.substring(0, (i + 1));
  tempWord += word[i];

  if(i !== (length - 1)) {
  tempWord += word.substring(i + 1);
 }
 typos.push(tempWord);
 }

 return typos;
 }

  // Get bit-squatting typos
  // Inspired by http://www.morningstarsecurity.com/research/urlcrazy
  function bitflipping(word) {
   var characters = word.split(''),
  masks = [128,64,32,16,8,4,2,1],
  allowed_chars = /[a-zA-Z0-9_\-\.]/,
  typos = [];

 for(var i = 0; i < characters.length; i++) {
 var c = characters[i],
 flipped = masks.map(function(mask) {
 return String.fromCharCode(c.charCodeAt(0) ^ mask).toLocaleLowerCase();
 }).filter(function(x) {
 return x.match(allowed_chars);
 });
  typos.push(flipped.map(function(x) {
 var e = word;
 return e.replaceAt(i, x);
 }));
  }

 return typos.reduce(function(a, b) {
 return a.concat(b);
 },'');
 }

 // Genereate Homephone Typos
  function homophoneTypos(word) {
  var homophones = getHomophones(),
  word = word.toLocaleLowerCase(),
  typos = [];

   for(var key in homophones) {
  if(word.indexOf(key) !== -1) { 
  homophones[key].forEach(function(homophone) {
  if(word.replace(new RegExp(key, "g"), homophone).replace(/ /g, '') !== word) {
 typos.push(word.replace(new RegExp(key, "g"), homophone).replace(/ /g, ''));
   }
   });
  }
}

  return typos;
  }

   keywords.forEach(function(keyword) {
   if(options.wrongKeys) {
   typos.push(wrongKeyTypos(keyword));
 }
 if(options.missedChars) {
 typos.push(missedCharsTypos(keyword));
 }
 if(options.transposedChars) {
 typos.push(transposedCharTypos(keyword));
 }
  if(options.doubleChars) {
 typos.push(doubleCharTypos(keyword));
 }
 if(options.flipBits) {
   typos.push(bitflipping(keyword));
 }
    if(options.generateHomophones) {
   typos.push(homophoneTypos(keyword));
  }
 });

  // Flatten the array of typos
  return typos.reduce(function(a, b) {
   return a.concat(b);
  }, '');
  };

  var input = process.argv, 
  keywords = input.splice(2);

  var typos = generateTypos(keywords, {
  wrongKeys: true,
  missedChars: true,
  transposedChars: true,
  doubleChars: true,
  flipBits: true,
  generateHomophones: true
  });
 typos.forEach(function(typo) {
 console.log(typo);
 });

new to javascript and node.js, please help me.

 Whenever I try to run the program I receive an error
 node.js:201
    throw e; // process.nextTick error, or 'error' event on first tick
          ^
 TypeError: Object  has no method 'forEach'
 at Object.<anonymous> (/home/chiranjit/Downloads/node-v0.10.20/typos.js:248:7)
 at Module._compile (module.js:441:26)
 at Object..js (module.js:459:10)
 at Module.load (module.js:348:32)
 at Function._load (module.js:308:12)
 at Array.0 (module.js:479:10)
 at EventEmitter._tickCallback (node.js:192:41)

I do not understand where is the error. Please help me with the following. How to get rid of TypeError: Object has no method 'forEach'. Also placed '' after the reduce functions as suggested. But then it throws the above error.

Answer 1

Basically, if you look at the stack trace you can see that the offending code is on line 194 in typos.js (which is line 196 in the file you have linked to). Array.reduce fails with a TypeError if the array is empty and there is no initial value specified. Providing an initiual value should help:

return typos.reduce(function(a, b) {
    return a.concat(b);
}, '');

Replace '' with the correct initial value, if needed.