Saif

With User defined settings  we can set values specific to build configuration. Creating User Defined Settings Select Target > Build Settings Click Plus icon, present beside the search bar Using User Defined Settings when we need to access the values set in User defined build settings we can do it in two ways  From info.plist $(NEW_SETTING) From Code let value = Bundle.main.infoDictionary?["NEW_SETTING"] as! String

The two basic rules of Memory Management are Objects obtained with  -alloc ,  -new ,  -copy , or  -mutableCopy  have a retain count of one. For objects created with any other method, assume they have a retain count of one but will be autoreleased . If you need to keep them in memory, you need to explicitly retain them. Lets see in detail how the memory management works, Memory management concepts are of critical importance and every Cocoa programmer should take the time to master them. Memory management in Cocoa comes in two flavors:  classic retain counts  and  garbage-collected . The question deals with the retain count flavor, so I will focus on that one. The retain count memory management scheme in Cocoa works on the basis that an object will remain in memory as long as other objects claim to be "interested in it." The Objective-C runtime keeps track of this "interested in" relationship with a simple number: the  retain c...

Structural Design Patterns in Swift Adapter : To unify the interfaces of incompatible classes that already exists Bridge : It decouples abstraction from its implementation, so that we can change them independently. It reduces the impact of changes Decorator : Used to add new responsibilities to objects without modifying the underlying classes Composite pattern : Describes how to combine objects so that each of them can be either simple or composite object. Facade : Allows us to expose functionality of entire sub system via single class Fly weight pattern : Used to effectively sharing no. of instances of a class by reducing number of object instances at runtime. Proxy pattern : Proxy objects acts as a surrogate for more complex objects that me expensive for create or use. Adapter : This pattern maps the existing interface to other interface. Eg., Two classes A and B are implementing a protocol P, so we use polymorphism to call the methods of A a...

Agile Manifesto: Many processes like Scrum, Kanban, Lean, Extreme Programming(XP), Crystal Clear, Agile Unified Process, Dynamic Systems Development Method, Feature Driven Development, Agile Modeling  what they were doing is same so they came up with Agile Manifesto which is set of 4 Values and 12 principals. The 4 Values are: Individuals and Interactions Over Process and tools: As process and tools avoid direct interactions the agile manifesto values Interactions. Working Software Over  Documentation: Giving value to Woking software than the document which describes the software. Customer collaboration Over Contract: We should not stick to contract, as technology changes. Responding to change over plan We should unfollow plans and de prioritise tasks which take longer time  The 12 Principles of Agile Manifesto: Underlying Agile Concepts: Short Feedback Loops Just in Time Requirements and Design Software does not need blue prints like before b...

Advanced Debugging Tips and Tricks: Injecting Code at runtime We can change values of variables at runtime while debugging (here variable_name is a Bool) expression variable_name = false  Here we are injecting value at runtime, so no need to run again to see the effect. (Other eg.,  expression animator.delegate = self) Under Xcode > Preferences > Behaviours > Running > Pauses > Check Show Tab Named, In order to show new tab while a breakpoint is hit. We can set other behaviours as well. We can add symbolic breakpoints on methods in frameworks. like This is in objective c because UIKit is in objective c. In order to find the values/parameter of a function inside framework, we can use For expression -[UILabel setText:] po $arg1 <UILabel ****> po (SEL)$arg2   "setText:" po $arg3 "0 ft" We can set symbolic breakpoints in 2 ways 1. By clicking plus in bottom left and choosing symbolic (Cons: Sets BP in all places) 2. By adding a breakpoi...

Apple introduced the following devices in todays event. Apple watch series 4 Ability to take an ECG using the watch. ECG data will be available in health app. It is FDA approved. Will be available in US on September 17th It also has fall detection and sends location update to emergency contacts. Larger screen size (30% larger) iPhone Xs and Xs Max (iOS 12) Water proof upto 2 meters for 30 mins Available in 5.8 inch super retina and 6.5 inch super retina display It has A12 Bionic Chip, first 7 nanometer chip, with 6.9 billion transistors, 6-Core CPU, which means it is 50% energy efficient and faster than previous A11 bionic. Use cases of Core ML, We can measure the leg angle and projectile path other metrics using HomeCourt App Ability to adjust the depth effect of already taken photos is another important feature. Dual Sim Capability. (Single physical sim and another eSim) Made with recyclable plastic and tin (for logic board)   iPhone Xr Ava...