问Javascript对重复的数组值进行计数，直到其发生变化

EN

/([a-z])\1*/gi

let array = ["a", "a", "a", "b", "b", "b", "b", "b", "c", "c", "c", "a", "d", "d"];
const result = array
  .join("")
  .match(/([a-z])\1*/gi)
  .map((s) => `${s[0]}${s.length}`);

console.log(result);

let chars =  ['a', 'a', 'a', 'b', 'b', 'b', 'b', 'b', 'c', 'c', 'c', 'a', 'd', 'd'];
const dic={}
for(char of chars){
    if(char in dic){
        dic[char]++;
    }else{
        dic[char]=1;
    }
}
console.log(dic);//{a: 4, b: 5, c: 3, d: 2}

let ara = ['a', 'a', 'a', 'b', 'b', 'b', 'b', 'b', 'c', 'c', 'c', 'a', 'd', 'd'];

let index = 0;
for (var i = 0; i < ara.length; i++) {

    let char = ara[i];
    let size = 0;

    let nextIndex = ara.findIndex(
        (a, index) => a !== char && index > i);
    if (nextIndex < 0) {
        size = ara.length - i;
        i = ara.length - 1;
    } else {
        size = nextIndex - i;
        i = nextIndex - 1;
    }
    console.log(char + ' ' + size);