不含重复元素的最长子串长度

// 不含重复元素的最长子串长度
let s = 'abcabbcb'

const judge = (s) => {
    return Array.from(s).length === Array.from(new Set(s)).length? true: false
}

const f = (s) => {
    let res = ''
    for (let i = 0; i < s.length; i++) {
        for (let j = i;j < s.length;j++) {
            if (judge(s.slice(i, j+1)) && res.length < s.slice(i, j+1).length) {
                res = s.slice(i, j+1)
            }
        }
    }
    return res.length
}