StringBuilder is faster one among string, stringbuffer and stringbuilder. Example public class Main { long startTime = 0l; long endTime = 0l; long timeDiff = 0l; // Concatenates to String public void concat1(String website) { startTime = System.nanoTime(); website = website + ".com"; endTime = System.nanoTime(); timeDiff = endTime – startTime; System.out.println("Time taken by String: … Read more

No, we cannot declare interface methods as static because static methods can not be overridden. Example interface Test1 { static void show(); }   public class Main { void show(){ System.out.println("Implmented method."); }   public static void main(String[] args) { Main object = new Main(); object.show(); } }interface Test1 { static void show(); } public … Read more

Yes, a class can implement two two interfaces with the same method signature but that method should be implemented only once in the class. Example interface Test1 { void show(); } interface Test2 { void show(); } public class Main { void show(){ System.out.println("Implemented method."); }   public static void main(String[] args) { Main object … Read more

The java.lang package is always imported by default in java.

No, Map is not a Collection type because it does not inherit from Collection interface. Collection Hierarchy   Map Hierarchy

Priority of Garbage Collector thread will be low. This is because of reason that the process of GC running is expensive, so rather than interrupt critical tasks it should only be done when the system has time to do. It is worked on the real time concept that is “do the unimportant task in the … Read more

No, array size cannot be negative. If we specify array size as negative, there will be no compile time error. But there will be run time NegativeArraySizeException. Example class Main { public static void main(String[] args) {   int[] testArray = new int[4];   for (int i = 0; i < testArray.length; ++i) { System.out.println(testArray[i]); … Read more

No, “abc” is not a primitive value. It is a string object. Example public class Main{ void show(){ System.out.println("abc".getClass().getName()); } public static void main(String args[]){ Main obj=new Main(); obj.show(); } }public class Main{ void show(){ System.out.println("abc".getClass().getName()); } public static void main(String args[]){ Main obj=new Main(); obj.show(); } } Output java.lang.Stringjava.lang.String

No, local inner class cannot be declared as private or protected or public because local inner class is not associated with Object. Example of local inner class public class Main{ private String website="826.a00.myftpupload.com"; void show(){ class LocalInnerClass{ void display(){ System.out.println(website); } } LocalInnerClass localInnerClass = new LocalInnerClass(); localInnerClass.display(); } public static void main(String args[]){ Main … Read more

No, true and false are not keywords in java. They are literals in java. As literals are reserved words in java so we cannot use them as identifiers in our program. Example public class Main { public static void main(String args[]){ int true = 10; String false = "jai"; } }public class Main { public … Read more