else value not reurning [duplicate]

This question already has an answer here:

• Javascript recursive function not returning value? 3 answers

function add(n){
    var arrtemp = n.toString().split('').map((e)=> parseInt(e))
    var temp = arrtemp.reduce((a,b)=> a+b);
    var arrtemp2 = temp.toString().split('').map((e)=> parseInt(e))
    if(arrtemp2.length>1 ){
        add(temp);
    }
    else {
        return (temp);
    }
}

I am trying to add the digits of a number and if the sum is 2 digit then it will again add the digits till the result is single digit. But the else statement is not returning the value.