Difference between compiler and interpreter
  • Compiler takes source code as input and interpreter takes bytecode as input.
  • Compiler generates bytecode as output while interpreter generates binary output.
  • Compiler compiles source code at once while interpreter compiles bytecode line by line.
  • Compiler only compile the source code while interpreter compiles and execute the bytecode.
  • Compiler is fast, interpreter is slow. 


Features of Java/buzzwords of Java.
  • Simple :- it is easily readable understandable and instructable.
  • Platform independent:- we can write any program in one platform and execute in any platform.
  • WORA:- Write Once Run Anywhere.
  • Highly secured:- execution of Java program happens inside GRE not inside operating system.
  • Robust:- Java check error twice one in the compile time and another in runtime.
  • Dynamic:- Java automatically allocated the memory to run the program and  automatically memory will be removed.
  • OOPS:- Object Oriented Programs.
  • Multi-threaded language:- we can write a program which can execute multiple jobs.
  • Free and open source software.




Datatype:







Types of datatype
  1. Inbuilt (primitive) 
  2. User defined (non-primitive)