BASIC INTERVIEW QUESTIONS IN JAVA
Tell us something about JIT compiler.
JIT stands for Just-In-Time and it is used for improving the performance during run
time. It does the task of compiling parts of byte code having similar functionality at
the same time thereby reducing the amount of compilation time for the code to run.
The compiler is nothing but a translator of source code to machine-executable code.
But what is special about the JIT compiler? Let us see how it works:
oFirst, the Java source code (.java) conversion to byte code (.class) occurs with
the help of the javac compiler.
oThen, the .class files are loaded at run time by JVM and with the help of an
interpreter, these are converted to machine understandable code.
oJIT compiler is a part of JVM. When the JIT compiler is enabled, the JVM
analyzes the method calls in the .class files and compiles them to get more
efficient and native code. It also ensures that the prioritized method calls are
optimized.
oOnce the above step is done, the JVM executes the optimized code directly
instead of interpreting the code again. This increases the performance and
speed of the execution.
Can you tell the difference between equals() method and equality operator (==) in
Java?
We are already aware of the,(==) equals,operator. That we have used this to
compare the equality of the values. But when we talk about the terms of object-
oriented programming, we deal with the values in the form of objects. And this
object may contain multiple types of data. So using the,(==) operator,does not
work in this case. So we need to go with the .equals() method.
Both,[(==),and,.equals()],primary functionalities are to compare the values, but the
secondary functionality is different.
So in order to understand this better, let’s consider this with the example -
String str1 = "InterviewBit";
String str2 = "InterviewBit";
System.out.println(str1 == str2);
Comment on method overloading and overriding by citing relevant examples.
