CODEWITHSUNDEEP
javascriptregex
bigbenbt
bigbenbt

Reputation: 367

Regex for extracting separate letters in a loop with javascript

I'm working on a script to create metrics for online author identification. One of the things I came across in the literature is to count the frequency of each letter (how many a's, how many b's, etc) independent of upper or lower case. Since I don't want to create a separate statement for each letter, I'm trying to loop the thing, but I can't figure it out. The best I have been able to come up with is converting the ASCII letter code in to hex, and then...hopefully a miracle happens.

So far, I've got

element = id.toLowerCase();
var hex = 0;
for (k=97; k<122; k++){
    hex = k.toString(16); //gets me to hex
    letter = element.replace(/[^\hex]/g, "")//remove everything but the current letter I'm looking for
    return letter.length // the length of the resulting string is how many times the ltter came up
}

but of course, when I do that, it interprets hex as the letters h e x, not the hex code for the letter I want.

Upvotes: 2

Views: 116

Answers (1)

Elliot Bonneville
Elliot Bonneville

Reputation: 53301

Not sure why you'd want to convert to hex, but you could loop through the string's characters and keep track of how many times each one has appeared with an object used as a hash:

var element = id.toLowerCase();
var keys = {};

for(var i = 0, len = element.length; i<len; i++) {
    if(keys[element.charAt(i)]) keys[element.charAt(i)]++;
    else keys[element.charAt(i)] = 1;
}

You could use an array to do the same thing but a hash is faster.

Upvotes: 5

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