Answer:
See explaination 
Step-by-step explanation:
function thanos(lst) {
 var result = [];
 for (var i = 0; i < lst.length; i += 2) {
 result.push(lst[i]);
 }
 return result;
}
// Testing the function here. ignore/remove the code below if not required
console.log(thanos([]));
console.log(thanos(['0', 2, 4]));