State pattern in LLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the interface for different states.

LLD

public interface State {
    void [1]();
}

Drag options to blanks, or click blank then click option'

Arun

Bstart

Chandle

Dexecute

Attempts:

3 left

💡 Hint

Common Mistakes

Using method names that do not clearly represent state behavior.

Choosing method names that are too generic or unrelated.

The handle method is commonly used in the State pattern to define the action for each state.

2fill in blank

medium

Complete the code to set the current state in the context class.

LLD

public class Context {
    private State state;

    public void setState([1] state) {
        this.state = state;
    }
}

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AState

BObject

CContext

DString

Attempts:

3 left

💡 Hint

Common Mistakes

Using a generic Object type instead of the State interface.

Using the Context class type instead of State.

The setState method accepts a parameter of type State to change the current state.

3fill in blank

hard

Fix the error in the state transition method to call the correct method on the current state.

LLD

public class Context {
    private State state;

    public void request() {
        state.[1]();
    }
}

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Aexecute

Bhandle

Crun

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Calling a method that does not exist in the State interface.

Using inconsistent method names between interface and implementation.

The request method should delegate the call to the handle method of the current state.

4fill in blank

hard

Fill both blanks to implement a concrete state class with the correct method and context reference.

LLD

public class [1]State implements State {
    private Context [2];

    public [1]State(Context context) {
        this.[2] = context;
    }

    @Override
    public void handle() {
        // state-specific behavior
    }
}

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AConcrete

BState

Ccontext

Dctx

Attempts:

3 left

💡 Hint

Common Mistakes

Using generic or unclear variable names for the context.

Mismatch between class name and constructor parameter.

The class name should be ConcreteState and the context reference variable is commonly named context for clarity.

5fill in blank

hard

Fill all three blanks to complete the context's constructor and initial state setup.

LLD

public class Context {
    private State [1];

    public Context() {
        this.[1] = new [2]State(this);
    }

    public void setState(State state) {
        this.[1] = state;
    }

    public void request() {
        [3].handle();
    }
}

Drag options to blanks, or click blank then click option'

Astate

BConcrete

Dcontext

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names for the state.

Incorrect class name for the initial state.

The context holds a state variable, initializes it with a ConcreteState instance, and calls state.handle() in the request method.