var arr = ['a', 'b', 'c'];
// push() - Add a new element into an array
arr.push('d');
// pop() - remove the last element of an array and return that element
arr.pop();
// concat() - concatenates to an array. This will not affect the original array
var newArr = ['e']
arr.concat(newArr);
// join() - This joins all the elements in an array to create a string and also will no modify the original Array
arr.join();
// reverse() - this reverses the elements in an . This will change the original array
arr.reverse();
// shift() - this will remove the first element in the array and return that element. This wiil change the original array
arr.shift();
// unshift('newArray') - add element to the begining of your array and return the length of the modified array
arr.unshift('newArr');
// slice() - this will select part of an array and return that new array you selected and the original array remain UNCHANGED
arr.slice(startAtIndexOne, endMinusOne);
// sort() - sort an array. this will change the original array
arr.sort();
// splice() - this is similar to slice(), but it will modify the original array instead of just returning new array.
// array.splice(start[, deleteCount[, item1[, item2[, ...]]]])
var months = ['Jan', 'March', 'April', 'June'];
months.splice(1, 0, 'Feb');
// inserts at 1st index position
console.log(months);
// expected output: Array ['Jan', 'Feb', 'March', 'April', 'June']
months.splice(4, 1, 'May');
// replaces 1 element at 4th index
console.log(months);
// expected output: Array ['Jan', 'Feb', 'March', 'April', 'May']
</script>