> For the complete documentation index, see [llms.txt](https://sagar-r-kothari.gitbook.io/blog/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sagar-r-kothari.gitbook.io/blog/_posts/2020-01-30-singlylinklist-insert-atend.md).

# 2020-01-30-SinglyLinkList-Insert-atEnd

```swift
import Foundation

class SinglyLinkListNode {
    let value: Int
    var next: SinglyLinkListNode?
    init(_ value: Int) {
        self.value = value
        next = nil
    }
}
```

```swift
struct SinglyLinkList {
    var head: SinglyLinkListNode?
    var tail: SinglyLinkListNode? {
        guard
            head != nil
            else { return nil }
        var currentNode = head
        while currentNode?.next != nil {
            currentNode = currentNode?.next
        }
        return currentNode
    }

    mutating func insertAtEnd(_ value: Int) {
        guard
            head != nil, let tail = tail
            else { head = SinglyLinkListNode(value); return }
        let node = SinglyLinkListNode(value)
        tail.next = node
    }
}
```