Responsive design is a technique that enables developers to adapt the layout and design of an app to suit multiple screen sizes. This is implemented using a series of CSS media queries that trigger layout and stylistic changes. These changes occur once a device property (such as screen width) meets… Continue reading
Fly weight pattern is useful where we need to create many objects and all these objects share some kind of common data. Consider figure ‘Objects and common data’. We need to print visiting card for all employees in the organization. So we have two parts of data one is the… Continue reading
Many times two classes are incompatible because of incompatible interfaces. Adapter helps us to wrap a class around the existing class and make the classes compatible with each other. Consider the below figure ‘Incompatible interfaces’ both of them are collections to hold string values. Both of them have a method… Continue reading
Visitor and strategy look very much similar as they deal with encapsulating complex logic from data. We can say visitor is more general form of strategy. In strategy we have one context or a single logical data on which multiple algorithms operate. In the previous questions we have explained the… Continue reading
Visitor pattern allows us to change the class structure with out changing the actual class. Its way of separating the logic and algorithm from the current data structure. Due to this you can add new logic to the current data structure with out altering the structure. Second you can alter… Continue reading
Strategy pattern are algorithms inside a class which can be interchanged depending on the class used. This pattern is useful when you want to decide on runtime which algorithm to be used. Let’s try to see an example of how strategy pattern works practically. Let’s take an example of a… Continue reading
State pattern allows an object to change its behavior depending on the current values of the object. Consider the figure ‘State pattern example’. It’s an example of a bulb operation. If the state of the bulb is off and you press the switch the bulb will turn off. If the… Continue reading
Observer pattern helps us to communicate between parent class and its associated or dependent classes. There are two important concepts in observer pattern ‘Subject’ and ‘Observers’. The subject sends notifications while observers receive notifications if they are registered with the subject. Below figure ‘Subject and observers’ shows how the application… Continue reading
Memento pattern is the way to capture objects internal state with out violating encapsulation. Memento pattern helps us to store a snapshot which can be reverted at any moment of time by the object. Let’s understand what it means in practical sense. Consider figure ‘Memento practical example’, it shows a… Continue reading
Many a times in projects communication between components are complex. Due to this the logic between the components becomes very complex. Mediator pattern helps the objects to communicate in a disassociated manner, which leads to minimizing complexity. Figure: – Mediator sample example Let’s consider the figure ‘Mediator sample example’ which… Continue reading