编辑代码

function getLongestSubStr(str){
    if(str.length <= 1) return str;
    let temp, max=0,left = 0, right = 1;
    while(right < str.length){
       temp = str.slice(left, right);
       if(temp.indexOf(str.charAt(right)) > -1){
           left++;
           continue;
       }else {
           right++
       }
       if(right - left > max ){
           max = right - left;

       }
    }
    return max;

}




const str='abcabcbb';
console.log(getLongestSubStr(str))