Important Interview Questions In Java For Freshers

-->What is the difference between '#include' we find in C language and 'import' that we find in Java?

A: '#include' makes the compiler to copy the entire header file code into a C or C++ program.So the program size increases and it wastes the memory and also the processor time

Import statement makes 'JVM' to go to java library,execute the code there and substitute the result into the Java program or application. In this case no code is copied.Therefore Import is more efficient than #include, as both memory along with processor time is saved.

-->What is Java Runtime Environment?(JRE)

A: JRE = JVM + Java Library.

-->What is uni-code system?

A:Uni-code is a standard to include the alphabet of all human languages into the character set of Java.
N:Uni-code uses two bytes to represent a single character.

-->What is the difference between Float and Double data types in Java?

A: Float can represent upto 7-digits after decimal point accurately, while double can represent upto 15-digits accurately after decimal point.