---
title: "What is KVO in iOS ?"  
description: "What is KVO in iOS ?"  
author: "Sunil Singh"  
published: 2017-01-02  
updated: 2020-09-22  
canonical: https://www.mindstick.com/interview/23125/what-is-kvo-in-ios  
category: "iphone"  
tags: ["iphone", "ios", "iphone sdk", "objective c"]  
reading_time: 1 minute  

---

# What is KVO in iOS ?

**Key-value observing** provides a mechanism that allows objects to be notified of changes to specific properties of other objects. It is particularly useful for communication between model and controller layers in an application.To observe a property using KVO you would identify to property with a string , using KVC (Key Value Coding) , Therefore, the observable object must be KVC compliant.

## Answers

### Answer by Sunil Singh

**Key-value observing** provides a mechanism that allows objects to be notified of changes to specific properties of other objects. It is particularly useful for communication between model and controller layers in an application.To observe a property using KVO you would identify to property with a string , using KVC (Key Value Coding) , Therefore, the observable object must be KVC compliant.


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Original Source: https://www.mindstick.com/interview/23125/what-is-kvo-in-ios

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