Edit in JSFiddle

let arr1 = [1, -2, 13, 4];
let arr2 = [3, 3, -5, 1];

let max = Math.max(...arr1);
console.log('Array-1 max',max);
let min = Math.min(...arr1);
console.log('Array-1 min',min);


console.log( 'Max of 2 arrays',Math.max(...arr1, ...arr2));