How to count Letters inside a string?

Question

My Code:

function letterCounter(str) {
    var letters = 0;
    var alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    for (var i=0; i<str.length;i++) {
        if (str[i] === alphabet.split("")) {
            letters = letters + str[i];
        }
    }
    console.log(letterCounter("Hello World!!!1"));
}

I am not sure what mistake I am making and I am getting 0 letters as my answer. Thank you.

You are also calling letterCounter from inside letterCounter. I think you want to move the console.log statement outside the last brace. — jeff carey, Sep 12 '16 at 13:43
What do you suggest I should instead of ` str[i] === alphabet.split("") ` — Blueman, Sep 12 '16 at 13:46
What should be the result of your example code? if you want result `15` you dont need this kind of function just `str.length` — Andurit, Sep 12 '16 at 13:47

score 7 · Accepted Answer · answered Sep 12 '16 at 13:49

You are comparing a character to an array in your code with str[i] === alphabet.split("") which makes no sense, you need to check if the character is inside the array. Also, the console.log must not be inside the function, or it will make it be called recursively infinite number of times.

Use

function letterCounter(str) {
    var letters = 0;
    var alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    var ar = alphabet.split("");
    for (var i=0; i<str.length;i++) {
        if (ar.indexOf(str[i]) > -1) {
            letters = letters + 1;
        }
    }
    return letters;
}
console.log(letterCounter("Hello World!!!1"));

Another way is to use a regex:

var s = "Hello World!!!1";
var rx = /[a-z]/gi;
var m = s.match(rx);
if (m) {
  console.log(m.length);
}

Andurit · Answer 2 · 2016-09-12T14:08:42.733

2

You can use regex for it:

function letterCounter (x) {
  return x.replace(/[^a-zA-Z]/g, '').length;
}

console.log(letterCounter('Hello World!!!1'))

edited Sep 12 '16 at 14:08

answered Sep 12 '16 at 13:52

Andurit

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`\w` matches letters, digits and an underscore. See my answer. `/[a-zA-Z]/g` or `/[a-z]/gi` is the correct regex for this. – Wiktor Stribiżew Sep 12 '16 at 13:53

score 1 · Answer 3 · answered Apr 14 '18 at 19:00

1

To calculate number count of the letter e for example:

var str = "Hello hello hello hello";
var lengthOfE = str.match(/e/gi).length;
console.log(lengthOfE);

Then use this in loop to calculate each element's count

answered Apr 14 '18 at 19:00

Black Mamba

8,408
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How to count Letters inside a string?

3 Answers3