Example: students = ["Ben" , "Ivy" , "Jordell"]
1) To add single elements to the end of an array, use the append(_:)
students.append(\ "Maxime" )
2) Add multiple elements at the same time by passing another array or a sequence of any kind to the append(contentsOf:) method
students.append(contentsOf: ["Shakia" , "William"])
3) To add new elements in the middle of an array by using the insert(_:at:) method for single elements
students.insert("Liam" , at:2 )
4) Using insert(contentsOf:at:) to insert multiple elements from another collection or array literal
students.insert(['Tim','TIM' at: 2 )