What is the string contained in s after following lines of code?

StringBuffer s = new StringBuffer(“Hello”); s.deleteCharAt(0);  ?

'ViewState' is specific to a page in a session.
'SessionState' is specific to user specific data that can be accessed across all pages in the web application.

There are lots of ways to solve the issue of callback hells:

1. Modularization: break callbacks into independent functions
2. Use a control flow library, like async
3. Use generators with Promises
4. Use async/await (note that it is only available in the latest v7 release and not in the LTS version)

Error-first callbacks are used to pass errors and data as well. You have to pass the error as the first parameter, and it has to be checked to see if something went wrong. Additional arguments are used to pass data.

fs.readFile(filePath, function(err, data) {
if (err) {
// handle the error, the return is important here
// so execution stops here
return console.log(err)
}
// use the data object
console.log(data)
})

The Spring Beans are Java Objects that form the backbone of a Spring application. They are instantiated, assembled, and managed by the Spring IoC container. These beans are created with the configuration metadata that is supplied to the container.
Beans defined in spring framework are singleton beans. There is an attribute in bean tag named "singleton" if specified true then bean becomes singleton and if set to false then the bean becomes a prototype bean. By default it is set to true. So, all the beans in spring framework are by default singleton beans.

The Spring IoC is responsible for creating the objects,managing them (with dependency injection (DI)), wiring them together, configuring them, as also managing their complete lifecycle.

The Panel and Applet classes use the FlowLayout as their default layout.

The window, Frame and Dialog classes use a border layout as their default layout.

A static method cannot access non static variables or methods because static methods doesnt need the object to be accessed. So if a static method has non static variables or non static methods which has instantiated variables they will no be intialized since the object is not created and this could result in an error.