Resizing

a = ['A','B','C','D'];  
console.log(a.length); // 4 
a.length = 3; 
console.log(a); // ['A', 'B', 'C'];  

// Proper way 
function resize(arr, newSize, defaultValue) { 
    return [ ...arr, ...Array(Math.max(newSize - arr.length, 0)).fill(defaultValue)]; 
}