How to create an empty array in Swift?

Inuyasha picture Inuyasha · May 25, 2015 · Viewed 257.2k times · Source

I'm really confused with the ways we create an array in Swift. Could you please tell me how many ways to create an empty array with some detail?

Answer

Dave G picture Dave G · Feb 15, 2016

Here you go:

var yourArray = [String]()

The above also works for other types and not just strings. It's just an example.

Adding Values to It

I presume you'll eventually want to add a value to it!

yourArray.append("String Value")

Or

let someString = "You can also pass a string variable, like this!"
yourArray.append(someString)

Add by Inserting

Once you have a few values, you can insert new values instead of appending. For example, if you wanted to insert new objects at the beginning of the array (instead of appending them to the end):

yourArray.insert("Hey, I'm first!", atIndex: 0)

Or you can use variables to make your insert more flexible:

let lineCutter = "I'm going to be first soon."
let positionToInsertAt = 0
yourArray.insert(lineCutter, atIndex: positionToInsertAt)

You May Eventually Want to Remove Some Stuff

var yourOtherArray = ["MonkeysRule", "RemoveMe", "SwiftRules"]
yourOtherArray.remove(at: 1)

The above works great when you know where in the array the value is (that is, when you know its index value). As the index values begin at 0, the second entry will be at index 1.

Removing Values Without Knowing the Index

But what if you don't? What if yourOtherArray has hundreds of values and all you know is you want to remove the one equal to "RemoveMe"?

if let indexValue = yourOtherArray.index(of: "RemoveMe") {
    yourOtherArray.remove(at: indexValue)
}

This should get you started!