SOURCE

var str = '222222222abbccccdddddeeeeeerrrrrrrrgggggggggg44444444444444'
console.log(str.length)
let c = 0
function getMaxLength(str) {
    const strLength = str.length
    const result = {
        code: '',
        count: 0
    }
    let a = 0
    let length = 0
    for (let i = 0; i < strLength; i++) {
        if (str[a] === str[i]) {
            length++
            console.log(length, '<-------length')
        }
        if (str[a] !== str[i] || i === strLength - 1) {
            if (length > result.count) {
                result.code = str[a]
                result.count = length
            }
            length = 0
            if (i < strLength - 1) {
                a = i
                i--
            }
        }
        c++
    }
    return result
}
const res = getMaxLength(str)

console.log('c------------->', c)
console.log(res)