What is key-value coding in IOS?
Key-value coding is a mechanism for accessing an object’s properties indirectly, using strings to identify properties, rather than through invocation of an accessor method or accessing them directly through instance variables. The above KVC working way is like working with Dictionaries in swift.
What is key-value in programming?
Key-value coding is a mechanism enabled by the NSKeyValueCoding informal protocol that objects adopt to provide indirect access to their properties. You typically use accessor methods to gain access to an object’s properties. A get accessor (or getter) returns the value of a property.
What is difference between KVC and KVO?
KVC stands for Key-Value Coding. It’s a mechanism by which an object’s properties can be accessed using string’s at runtime rather than having to statically know the property names at development time. KVO stands for Key-Value Observing and allows a controller or class to observe changes to a property value.
What is lazy keyword in Swift?
A lazy stored property is a property whose initial value isn’t calculated until the first time it’s used. You must always declare a lazy property as a variable (with the var keyword), because its initial value might not be retrieved until after instance initialization completes.
What is key-value coding Swift?
According to Apple: Key-value coding is a mechanism for accessing an object’s properties indirectly, using strings to identify properties, rather than through invocation of an accessor method or accessing them directly through instance variables.
What is key-value example?
A key-value pair is the fundamental data structure of a key-value store or key-value database, but key-value pairs have existed outside of software for much longer. A telephone directory is a good example, where the key is the person or business name, and the value is the phone number.
Is MongoDB a key-value database?
MongoDB as a key-value store The ability of MongoDB to efficiently store flexible schema documents and perform an index on any of the additional fields for random seeks makes it a compelling key-value store.
What is KVC and KVO in IOS?
Objective-C Key Value Coding(KVC) vs Key Value Observing(KVO) [Swift KVC] KVC allows you to access to property by String it is enabled for all NSObject successors.
What is key value observing Swift?
Key-value observing is a mechanism that enables an object to be notified directly when a property of another object changes. It is a mode of communication between objects in applications designed in conformance with the Model-View-Controller design pattern.