JSFiddle - React, Tailwind, and code Playground
JavaScript
var str = "aadddbcbcdbca"
var uniq = {}
var exists = 0
str.forEach(s => {
uniq[s] = s
if(uniq[s]){
exists++
} else {
exists = 0
}
if (exists.length === uniq.length) {
}
})