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Articles by Nitin Aggarwal
Page 6 of 14
Objective-C and Swift URL encoding
URL encoding is an essential part of iOS app development. Many times, you will need to encode the URL to communicate with servers. Let's look at some examples of how you can encode an URL in Swift and Objective-C. URL Encoding in Swift In Swift, you can use the addingPercentEncoding(withAllowedCharacters:) method for URL encoding. URL Encoding in Objective-C In Objective-C, you can use the stringByAddingPercentEncodingWithAllowedCharacters method for URL encoding. Encode a URL in Objective-C In Objective-C, you can encode a URL string using the stringByAddingPercentEncodingWithAllowedCharacters: method of the NSString class. Here's an example NSString *stringToEncode = @"https://www.exampleserver.com/complete path with spaces"; ...
Read MoreNew Array from Index Range Swift
In Swift, you can create an array using the ArraySlice type. The following examples will show how to use the ArraySlice type. You can create an extension as well to define the subscript method. Example 1 In the following example, we create an array of numbers with values from 0 to 9 and then create a range of indices from startIndex to endIndex (exclusive). Using this range we can generate an ArraySlice of the original array. In the end, we will convert the ArraySlice to an array using the Array initializer and print the result. import Foundation let numbers = ...
Read MoreMultiple Type Constraints in Swift
In Swift, there are several ways to implement type constraints on types. We will use some common approaches like the where clause, protocol, etc. Generics provide lots of flexibility to write better and more secure code in Swift. We can apply generics to collections, custom types, etc. One of them is generic type constraints. Using type constraints, you can make your generic code behave that matches a certain set of constraints whatever you define. Swift provides multiple ways to specify type constraints on generic type parameters. Type constraints using the "where" clause The "where" clause in Swift is a highly ...
Read MoreHow to assign an action to the UIImageView object in Swift?
In the iOS applications, the UIImageView class does not provide in-build support to make it clickable like other components e.g. UIButton. In order to make UIImageView clickable, you can add a UITapGestureRecognizer to the image view. Remember that, by default, UIImageView does not take any interaction from the user. To make it interactable, set true to the isUserInteractionEnabled property. In this article, you will learn how you can add a tag gesture to the image view in Swift. To add a tap gesture, we will follow these steps − Step 1 - Create an Image View let profileImageView = ...
Read MoreHow to test the equality of Swift enums with associated values?
In Swift, you can use the Equatable protocol to compare enums with associated values. In this article, we will see how we can compare them using the Equatable protocol with an example. Enumeration with Associated Values In Swift, you can provide a value along with an enum case. This makes enumeration more powerful in Swift. A Swift feature called an enumeration with associated values enables you to design a type that can have a finite set of cases, each of which can have a unique set of associated values of any type. This enables you to link data to each ...
Read MoreHow can I encode a string to Base64 in Swift?
In Swift, you can use the built-in Data type and its method base64EncodedString() to encode a string to Base64. In the iOS applications, you might need to encode a string to base64 mostly in networking requests and responses. Mostly, you will need to encode a string to base64 and vice versa. Let's learn how to encode a string to Base64 using Swift. Example In this example, we will use the following steps to encode a string to base64 − Step 1 − In this step, we will convert the string to a Data object using the data(using: .utf8) method. ...
Read MoreHow do I make an enum decodable in Swift?
In Swift, you can use the Codable protocol to make an enum decodable as well. In Swift, the Codable protocol is a very powerful concept to provide flexibility to decode and encode any type of value. Also, you can make an enum decodable as well. You have to just define an enum in your custom type. In order to make an enum decodable, the enum must conform to the Codable protocol. In this article, we will learn how to use the Codable protocol to make an enum decodable in Swift What is the JSONDecoder Class? The JSONDecoder class is then ...
Read MoreHow to convert a JSON string to a dictionary in Swift?
Swift provides a class called JSONSerialization to convert a JSON string to dictionary format. For example, you are receiving a JSON string from the database, in order to use it in the application, you might need to convert it into a real object type. In this article, you will see some examples of how to convert a JSON string into a dictionary. What is JSON String? A JSON string is a string that is converted to a different format such as base64 or URL encoding. This converted string can be used for networking requests or to store in the database. ...
Read MoreHow to convert a number to an absolute value in Swift?
To convert a number to its absolute value in Swift, you can use the abs(_:) function. In this article, you will see multiple examples of how to use the abs() function in the Swift language. Example 1 In this example, you will convert a simple negative number to an absolute value. Step 1 − Declare an input variable with an initial numeric value Step 2 − Convert the numeric input value into absolute value using the abs() function Step 3 − Assign the output absolute value to a new variable Step 4 − Print the input value to the ...
Read MoreArray extension to remove an object by value in Swift
To remove an object by value from an array in Swift, you can create an extension to the Array type. You can then call the function that takes the value to eliminate as a parameter. In this article, we will use the filter function to remove an object passing by value in the Swift language. Let's see some examples of how you can eliminate an object by value from an array Example 1: Remove an Object Using the Filter Function You can use the built-in filter method to create a new array without the matching value. Algorithm Step 1 ...
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