Node.js -HK3

hk3.js

function map(arr,fun){
    for(let i=0;i<arr.length;i++)  
        arr[i] = fun(arr[i])
    return arr;
}

const arr = [1,2,3,4,5]

const new_arr = map(arr,function(n){
    return n*100
});

console.log(new_arr);

output

[ 100, 200, 300, 400, 500 ]