Untitled

let caps=["MO","TU","WE", "TH", "FR","SA","SU"]
let week=['Mon', "Tue", "Wed", "Thur","Fri","Sat","Sun"]
const getweek=(inp)=>{
    var temp=[]
    for(i of inp){
        let id=caps.indexOf(i)
        temp.push(week[id])
    }
    console.log(temp);
}
var input=[ "TH", "FR"]

getweek(input)