ios - How to check if array is null or empty?

Ios - How to check if array is null or empty?

In Swift, you can check if an array is null or empty using the following approaches:

  1. Checking for nil and Empty: If the array is declared as an optional ([Type]?), you can use optional binding (if let or guard let) to check for nil and then check if it's empty.

    var myArray: [Type]? = [...] // Your array or nil if let array = myArray, !array.isEmpty { // Array is not nil and not empty } else { // Array is nil or empty }

  2. Using Nil Coalescing Operator: If you want to provide a default array in case the original array is nil, you can use the nil coalescing operator (??).

    var myArray: [Type]? = [...] // Your array or nil let nonNilArray = myArray ?? [] if !nonNilArray.isEmpty { // Array is not empty } else { // Array is empty }

  3. Checking for Empty Without Considering nil: If you're certain that the array is not nil (i.e., it's non-optional), you can directly check if it's empty.

    var myArray: [Type] = [...] // Your array if !myArray.isEmpty { // Array is not empty } else { // Array is empty }

Choose the approach that best fits your scenario based on whether the array is optional or non-optional and whether you want to provide a default array in case of nil.

Examples

  1. Swift code to check if an array is empty:

    if myArray.isEmpty { // Array is empty } else { // Array is not empty }

    Description: This Swift code uses the isEmpty property to check if the array is empty.

  2. Objective-C code to check if an array is empty or nil:

    if (!myArray || [myArray count] == 0) { // Array is empty or nil } else { // Array is not empty }

    Description: This Objective-C code checks if the array is empty or nil using conditional statements.

  3. Swift code to determine if an array is nil or empty using guard:

    guard let myArray = myArray, !myArray.isEmpty else { // Array is nil or empty return } // Array is not empty

    Description: Uses the guard statement to safely unwrap the array and check if it's not empty.

  4. Checking for an empty array in Swift with optional chaining:

    if let myArray = myArray, !myArray.isEmpty { // Array is not nil and not empty } else { // Array is nil or empty }

    Description: Utilizes optional chaining to safely check if the array is not nil and not empty.

  5. Objective-C code to check if an NSArray is empty or contains elements:

    if (!myArray || [myArray count] == 0) { // NSArray is empty or nil } else { // NSArray is not empty }

    Description: Similar to query 2, specifically for NSArray.

  6. Swift code to check if an array is nil or has elements using if-let:

    if let myArray = myArray, myArray.count > 0 { // Array is not nil and has elements } else { // Array is nil or empty }

    Description: Combines optional binding with a count check to determine if the array is not nil and not empty.

  7. iOS Swift code to handle optional array safely:

    if let myArray = myArray { if !myArray.isEmpty { // Array is not nil and not empty } else { // Array is nil or empty } } else { // Array is nil }

    Description: Nested if-let statements to safely handle optional arrays.

  8. Checking if an array is empty or nil in Swift using ternary operator:

    let isEmpty = myArray?.isEmpty ?? true if !isEmpty { // Array is not empty } else { // Array is nil or empty }

    Description: Uses the nil-coalescing operator to handle the case where the array is nil.

  9. Swift code to check for an empty or nil array using a custom function:

    func isNullOrEmpty(_ array: [Any]?) -> Bool { return array == nil || array!.isEmpty } // Usage: isNullOrEmpty(myArray)

    Description: Provides a reusable function to check if an array is nil or empty.

  10. Swift code to check if an array is nil, empty, or contains only nil values:

    let containsOnlyNil = myArray?.allSatisfy { $0 == nil } ?? true if containsOnlyNil { // Array is nil, empty, or contains only nil values } else { // Array contains non-nil values }

    Description: Uses allSatisfy to check if the array is nil, empty, or contains only nil values.

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