Methods and Strings

Question 1

methods declaration has two parts

Answer 1

method header, method body

Question 2

method header defines …

Answer 2

name, parameters, return type

Question 3

method body is the…

Answer 3

actual body of the method that defines its logic

Question 4

final methods can be overridden ?

Answer 4

false

Question 5

abstract must be?

Answer 5

must be overridden has an empty body in parent class but no in child classes

Question 6

method overloading is

Answer 6

having more than one method with the same name but with different parameter types or different number of parameters

Question 7

return type cannot be used to overload method ?

Answer 7

true

Question 8

parameters in java are passed by value?

Answer 8

true

Question 9

if the parameter is an object then what is passed? (value or reference)

Answer 9

it is the object reference is passed

Question 10

this keyword references

Answer 10

to the object from which is called

Question 11

main method

Answer 11

public static void main(String[] args)

Question 12

why main method is public?

Answer 12

to be accessed from the outside

Question 13

why static main method?

Answer 13

so no instantiation required

Question 14

why string[] args ?

Answer 14

pass parameters to the program

Question 15

when a object is eligible for garbage collection? it will be

Answer 15

deleted by garbage collector

Question 16

when is an object eligible for garbage collection?

Answer 16

when the reference is null or

if the object reference is made to reference to another object

Question 17

how to force a garbage collector to work

Answer 17

system.gc

Question 18

strings is considered a

Answer 18

sequence of characters

Question 19

strings are … (immutable- mutable)

Answer 19

immutable

Question 20

what does strings are immutable mean?

Answer 20

means their value cant be changed , they simply reference to another place in memory and add the new value to it they dont change directly

Question 21

to convert any object to string you should override

Answer 21

the method toString()

Question 22

to compare strings we use

Answer 22

equals()

Question 23

== operator can be used to compare strings

Answer 23

no , it compares addresses only

Question 24

compare to returns what when it s1 = s2

Answer 24

0

Question 25

substring method returns

Answer 25

substring starting position and ends at another position

Question 26

indexof returns

Answer 26

finds a substring if exists and returns its positions (-1 if not found)