Runtime vs. Compile time

Question

What is the difference between run-time and compile-time?

Answer 1

Look into this example:

public class Test {

    public static void main(String[] args) {
        int[] x=new int[-5];//compile time no error
        System.out.println(x.length);
    }}

The above code is compiled successfully, there is no syntax error, it is perfectly valid. But at the run time, it throws following error.

Exception in thread "main" java.lang.NegativeArraySizeException
    at Test.main(Test.java:5)

Like when in compile time certain cases has been checked, after that run time certain cases has been checked once the program satisfies all the condition you will get an output. Otherwise, you will get compile time or run time error.