Basic data types Array.js

// DESCRIPTION:
// In javascript, Array is one of basic data types. To define an empty array, you can use var arr=new Array() or var arr=[]

// Array has an attribute: length, if there is an array named arr, using arr.length to know how many elements are contained in the array.

// Each element in the array has an index, use arr[index] to get the value of element.

// index always start from 0, so the first element of array is arr[0], the last element of array is arr[arr.length-1].

// If we want to add new elements to the array, you can use the array method: push(). It can add an element to the end of the array. Instead, if we want to remove the last element of the array, you can use the array method: pop(). for example:

// var arr=[1,2,3];     //define an array arr contains elements 1 2 3
// arr.push(4);         //add element 4 to arr
// console.log(arr)     //[1,2,3,4]
// arr.pop();           //remove the last element from arr
// console.log(arr)     //[1,2,3]
// Task
// I've written five functions. Each function receives a parameter arr which is an array. Complete the functions using arr inside the function bodies.

//     1. getLength(arr)    should return length of arr
//     2. getFirst(arr)     should return the first element of arr
//     3. getLast(arr)      should return the last element of arr
//     4. pushElement(arr)  should push an element to arr, and then return arr
//     5. popElement(arr)   should pop an element from arr, and then return arr
// When you have finished the work, click "Run Tests" to see if your code is working properly.

// In the end, click "Submit" to submit your code pass this kata.


// My Solution
function getLength(arr){
  return arr.length
}
function getFirst(arr){
  //return the first element of arr
  return arr[0]
}
function getLast(arr){
  //return the last element of arr
  return arr[arr.length-1]
}
function pushElement(arr){
  var el=1;
  //push el to arr
  arr.push(el)
  
  return arr
}
function popElement(arr){
  //pop an element from arr
  
  arr.pop()
  return arr
}