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Java Multithreading for Senior Engineering Interviews

Printing Foo Bar n Times

Understand how to coordinate two threads in Java to print Foo and Bar alternately n times. Learn to use synchronization with wait and notifyAll methods to control thread execution order and ensure correct output sequence.

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Problem Statement

Suppose there are two threads t1 and t2. t1 prints Foo and t2 prints Bar. You are required to write a program which takes a user input n. Then the two threads print Foo and Bar alternately n number of times. The code for the class is as follows:

class PrintFooBar {  
    
    public void PrintFoo() {    
        for (int i = 1 i <= n;  i++){
        System.out.print("Foo");    
        }  
    }

    public void PrintBar() {    
        for (int i = 1; i <= n; i++) {      
        System.out.print("Bar");    
        }  
    }
}

The two threads will run sequentially. You have to synchronize the two threads so that the functions PrintFoo() and PrintBar() are executed in an order. The workflow is shown below:

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