None, as C was made prior to Java.
C, C++ and Java are cross-platform languages. NET is for Windows-only.
The Java native method is a great way to gain and merge the power of C or C++ programming into Java. To use Java as a scientific and high performance language, when efficient native Java compilers are not fully implemented, use native method can boost the performance to at least the speed of C compiled code.
Languages where all types, including primitive types such as integers, are implemented as objects. Java is a pure object oriented language. C++ is not pure because integers, floating point values and pointers are primitive data types that are not implemented as objects. As a result, Java is easier to program, but C++ is more efficient.
As there are more than one JVM implementations, there is not a single language used to implement them all. Off the top of my head, I can list JVMs that are implemented in C, C++, Java (yes, a JVM in Java), Objective C, and even one in Javascript (don't ask why).
No. The term platform independence in Java does not mean that any other programming language cannot be run in multiple OS platforms. Actually platform independence means that the java code can be run in multiple platforms with little or no customization. The code that can execute in a Windows platform can run as it is in a Linux box, whereas other programming languages need to be customized based on the platform they will be implemented in.
If by interface you mean, a mechanism to achieve abstraction and create a blueprint for future implementation. Java/C#/C++ all allow for multiple interfaces(abstract classes in C++) to be implemented.
Java is not similar to C. Java is, however, similar to C++. Both C++ and Java are object orientated programming languages (OOPL's).
A header file in C is used to import the features of parent classes in our class. The same feature is provided by the import statement in Java hence the header files are not used.
Pointers is a very powerful feature that is available in the C programming language but at the same time it is very confusing and many of the issues that arise out of C programs is because of incorrect or inappropriate usage of pointers. Hence the creators of Java language opted to exclude the pointers feature and create Java as a language where the programmer cannot access the native memory area and the memory accessing is left to the system to be taken care of.
Java is object oriented, C is not...
Java does not require header files like C/C++.
Java is considerably easier than C++.