Java Interview Questions and Answers - 1

Question: 1

What is a platform?

A platform is the hardware or software environment in which a program runs.

Most platforms can be described as a combination of the operating system and hardware, like Windows 2000/XP, Linux, Solaris and MacOs.

Question: 2

Can Java code be compiled to machine dependent executable file?

Yes. There are many tools out there. If you did so, the generated exe file would be run in the specific platform, not cross plat-form.

Question: 3

Why classes in java are immutable?

All wrapper classes in java.lang are immutable –

String,

Integer,

Boolean,

Character,

Byte,

Short,

Long,

Float,

Double,

BigDecimal,

BigInteger.

Question: 4

What is the difference between static and non static variables?

A static variable is associated with the class as a whole rather than with specific instances of a class.

Non static variables take on unique values with each object instance.

Question: 5

What is a pointer?

Pointer means a reference handle to memory location.