Answers for "count of particular letter in a string js"

javascript count occurrences of letter in string

function count(str, find) {
    return (str.split(find)).length - 1;
}

count("Good", "o"); // 2

how to count specific letters in string js

console.log(("str1,str2,str3,str4".match(/,/g) || []).length); //logs 3

console.log(("str1,str2,str3,str4".match(new RegExp("str", "g")) || []).length); //logs 4