Given a string aaabbbcccooeellmmzzz how can I count the number of characters that comes after 'm'.
For example in this case it should return 5 (i.e oozzz);
Note: Here o and z characters come after 'm' in alphabetical order not about their index position after m.
So i want to count the characters (n,o,p,q,r,s,t,u,v,w,x,y,z) as many times they appear in the string.
Sample Input : aaabbbcccooeellmmmzzz
Sample Output: 5
Use substring to remove everything from the start to the index of the last occurrence of the character, then get the length:
let character = 'm';
let str = 'aaabbbcccooeellmmmzzz';
let res = str.substring(str.lastIndexOf(character) + 1).length;
console.log(res)