function reversArray(){
for (let i = 0; i < arr.length; i++) {
for (let j = i + 1; j < arr.length; j++) {
let c, a, b;
b = arr[i];
arr[i] = arr[j];
arr[j] = b;
}
}console.log(arr);
}
let arr = [1, 12, 15, 16, 78, 89, 53 ,'hi'];
reversArray(arr);