2.js

// 2. Write a JavaScript function to get the first element of an array. Passing a parameter 'n' will return the first 'n' elements of the array. 
// Test Data : 
// console.log(first([7, 9, 0, -2])); 
// console.log(first([],3));
// console.log(first([7, 9, 0, -2],3));
// console.log(first([7, 9, 0, -2],6));
// console.log(first([7, 9, 0, -2],-3));
// Expected Output : 
// 7
// [] 
// [7, 9, 0] 
// [7, 9, 0, -2] 
// [] 

var first =  (array, n) => {
    if (array == null) 
    return void 0;
if (n == null) 
    return array[0];
if (n < 0)
    return [];
return array.slice(0, n);
};

console.log(first([7, 9, 0, -2]));
console.log(first([],3));
console.log(first([7, 9, 0, -2],3));
console.log(first([7, 9, 0, -2],6));
console.log(first([7, 9, 0, -2],-3));