[Term Entry] Swift Arrays: dropFirst() (#7403)

Author: mamtawardhani

content/swift/concepts/arrays/terms/dropFirst/dropFirst.md

@@ -0,0 +1,102 @@
+---
+Title: 'dropFirst()'
+Description: 'Returns a subsequence by skipping the first element or first n elements from a Swift collection.'
+Subjects:
+  - 'Computer Science'
+  - 'Mobile Development'
+Tags:
+  - 'Arrays'
+  - 'Collections'
+  - 'Swift'
+CatalogContent:
+  - 'learn-swift'
+  - 'paths/build-ios-apps-with-swiftui'
+---
+
+In Swift, the **`dropFirst()`** method is used on collections like [arrays](https://www.codecademy.com/resources/docs/swift/arrays), strings, and other sequences to return a subsequence with the first element (or first _n_ elements) removed. It doesn’t mutate the original collection, but returns a new subsequence starting from the dropped position.
+
+## Syntax
+
+```pseudo
+collection.dropFirst(n)
+```
+
+**Parameters:**
+
+- `n` (Optional): An `Int` representing the number of elements to skip. If omitted, it defaults to 1.
+
+**Return value:**
+
+Returns a `SubSequence` meaning a view into the original collection with the specified number of leading elements removed.
+
+## Example 1: Removing the First Element from an Array
+
+This example drops the first item in an array of numbers:
+
+```swift
+let scores = [90, 85, 80, 75]
+let updatedScores = scores.dropFirst()
+
+print(updatedScores)
+```
+
+The output of this code is:
+
+```shell
+[85, 80, 75]
+```
+
+## Example 2: Dropping the First 3 Names from a List
+
+This example skips the first three values in an array of strings:
+
+```swift
+let names = ["Alice", "Bob", "Charlie", "Dana", "Eve"]
+let remaining = names.dropFirst(3)
+
+print(remaining)
+```
+
+The output of this code is:
+
+```shell
+["Dana", "Eve"]
+```
+
+## Example 3: Converting Result Back to an Array
+
+Since `dropFirst()` returns a `SubSequence`, use `Array()` to convert the result when you need an actual array:
+
+```swift
+let data = [1, 2, 3, 4, 5]
+let trimmed = Array(data.dropFirst(2))
+
+print(trimmed)
+```
+
+The output of this code is:
+
+```shell
+[3, 4, 5]
+```
+
+## Frequently asked questions
+
+### 1. What is the type of an array in Swift?
+
+In Swift, arrays are generic collections. This means the type of array depends on the type of elements it holds. For example:
+
+- `let numbers: [Int] = [1, 2, 3]` is an array of integers (`[Int]`)
+- `let names: [String] = ["Alice", "Bob"]` is an array of strings (`[String]`)
+
+### 2. Are Swift arrays dynamic?
+
+Yes, Swift arrays are dynamic. This means they can grow or shrink in size:
+
+- You can append new elements using `.append()` or `+=`
+- You can remove elements using `.remove(at:)`, `.removeFirst()`, etc.
+
+### 3. What is the difference between `dropFirst()` and `removeFirst()` in Swift?
+
+- `dropFirst()` returns a new array after skipping the first element (or a specified number of elements) without modifying the original array.
+- `removeFirst()` removes and returns the first element (or first `n` elements) from the original array, modifying it in place.