Which methods in Java do you consider the most important and most frequently used?

main(String[] args) is the entry point of a Java application.

equals(Object obj) compares objects by their content.

hashCode() returns the hash code of an object, important for collections like HashMap and HashSet.

toString() provides a string representation of the object.

clone() creates a copy of the object (when implementing Cloneable).

run() is the main method for executing code in a separate thread (interface Runnable, class Thread).

start() launches a new thread (class Thread).

wait(), notify(), notifyAll() are used for thread synchronization in multithreading.

size() gets the size of a collection (List, Set, Map, etc.).

add(), addAll() add elements to collections.

get() retrieves an element by index (for List).

put(), putAll() add key-value pairs to a Map.

remove() deletes elements from collections.

iterator() gets an iterator for traversing collection elements.

hasNext(), next() are iterator methods for collection traversal.

close() releases resources (for classes implementing Closeable or AutoCloseable).

trim() removes spaces from the edges of a string.

split() splits a string into an array of strings based on a delimiter.

substring() gets a substring.

length() gets the length of a string or array.

valueOf() converts other data types to string.

parseInt(), parseDouble(), etc., convert strings to primitive data types (in wrapper classes like Integer, Double, etc.).

getMessage() retrieves the error message in exceptions.

printStackTrace() outputs the call stack during an exception.

currentTimeMillis() gets the current time in milliseconds (System class).

gc() requests garbage collection (System and Runtime classes).

exit() terminates the application (System class).

forName() loads a class by name (Class class).

newInstance() creates a new instance of a class (Class class).

loadClass() loads a class (ClassLoader class).