Explanation: isAlive() method is used to check whether the thread being called is running or not, here thread is the main() method which is running till the program is terminated hence it returns true. 10. What will be the output of the following Java code?
Life cycle of a Thread (Thread States) A thread can be in one of the five states. According to sun, there is only 4 states in thread life cycle in java new, runnable, non-runnable and terminated. There is no running state. ... The life cycle of the thread in java is controlled by JVM.
A thread goes through various stages in its lifecycle. ... Runnable − After a newly born thread is started, the thread becomes runnable. A thread in this state is considered to be executing its task. Waiting − Sometimes, a thread transitions to the waiting state while the thread waits for another thread to perform a task.
A thread can be created by implementing the Runnable interface and overriding the run() method. Then a Thread object can be created and the start() method called. The Main thread in Java is the one that begins executing when the program starts.
Example 1: call the run() method using the start() method
For identification purposes, hydraulic tube fittings and connectors can be divided into six different thread types: UN/UNF, NPT/NPTF, BSPP (BSP, parallel), BSPT (BSP, tapered), metric parallel, and metric tapered.
(Entry 1 of 2) 1a : a filament, a group of filaments twisted together, or a filamentous length formed by spinning and twisting short textile fibers into a continuous strand. b : a piece of thread. 2a : any of various natural filaments the threads of a spiderweb.
start method of thread class is implemented as when it is called a new Thread is created and code inside run() method is executed in that new Thread. While if run method is executed directly than no new Thread is created and code inside run() will execute on current Thread and no multi-threading will take place.
The purpose of start() is to create a separate call stack for the thread. A separate call stack is created by it, and then run() is called by JVM. Let us see what happens if we don't call start() and rather call run() directly.
No, you can not directly call run method to start a thread. You need to call start method to create a new thread. If you call run method directly , it won't create a new thread and it will be in same stack as main. As you can see when we are directly calling run method, it is not creating new threads.
After starting a thread, it can never be started again. ... If you does so, an IllegalThreadStateException is thrown. In such case, thread will run once but for second time, it will throw exception.
Within a process or program, we can run multiple threads concurrently to improve the performance. Threads, unlike heavyweight process, are lightweight and run inside a single process – they share the same address space, the resources allocated and the environment of that process.
Any method that touches the Vector 's contents is thread safe. ArrayList , on the other hand, is unsynchronized, making them, therefore, not thread safe. With that difference in mind, using synchronization will incur a performance hit. So if you don't need a thread-safe collection, use the ArrayList .
Which two are valid constructors for Thread? Explanation: (1) and (2) are both valid constructors for Thread. (3), (4), and (5) are not legal Thread constructors, although (4) is close.
What decides thread priority? Explanation: Thread scheduler decides the priority of the thread execution. This cannot guarantee that higher priority thread will be executed first, it depends on thread scheduler implementation that is OS dependent. 4.
Since a Thread can not be restarted you have to create a new Thread everytime. A better practice is to separate the code to run in a thread from a Thread 's lifecycle by using the Runnable interface. Just extract the run method in a class that implements Runnable . Then you can easily restart it.
Which of the following will directly stop the execution of a Thread? Explanation: . wait() causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object.
Background Information: Java Threads The default priority of a Java thread is NORM_PRIORITY . (A Java thread that doesn't explicitly call setPriority runs at NORM_PRIORITY .) A JVM is free to implement priorities in any way it chooses, including ignoring the value.
One or more Threads runs in the context of process. Threads can execute any part of process. And same part of process can be executed by multiple Threads. Processes have their own copy of the data segment of the parent process while Threads have direct access to the data segment of its process.
Explanation : : A thread dies when the execution of the run( ) method ends. The call to the start method is asynchronous, that is, it returns immediately, and it enables the thread for running. Calling the sleep( ) or wait( ) methods will only block the thread temporarily.
Once a thread enters dead state it cannot be restarted.
Reason : A thread dies when the execution of the run( ) method ends. The call to the start method is asynchronous, that is, it returns immediately, and it enables the thread for running. Calling the sleep( ) or wait( ) methods will only block the thread temporarily.
10) What does the expression float a = 35 / 0 return? Explanation: In Java, whenever we divide any number (double, float, and long except integer) by zero, it results in infinity. ... But on dividing an integer by zero, it throws a runtime exception, i.e., java.lang.ArithmeticException.
What is true about constructor? Explanation: Constructor returns a new object with variables defined as in the class. Instance variables are newly created and only one copy of static variables are created. ... Abstract class cannot have a constructor.
The correct answer to the question “Which statement is true about Java” is, option (a). Platform independent programming language. As we already know that Java is a platform-independent language, which functions on a set principle “compile once, and run everywhere”.
Explanation: Yes, it is correct that Java is a popular programming language which is object-oriented and interpreted programing language also.