Exercise 1 OOP

Define (System.in ) in Java code

• Wraps another Reader and improves performance.

• The flow of data to a program from an input device

• The flow of data from a program to an output device

• Provides a readLine method to read a line of text.

Predict the following program output

class question4{ public static void main ( String[] args )

{ int totalCost = 6;

int items = 12;

System.out.println("cost per item: " + totalCost/items );

}}

• cost per item: 2

• cost per item: 0

• cost per item: 0.5

• cost per item: +6/12

Choose a code to declare an array and initialize it with five numbers

• int a [] = new int(5);

• int [5] array;

• int [] a = (23,22,21,20,19);

• int [] a = {23,22,21,20,19};

Determine the output for the following code segment

int count=1;

while(count<=3)

{ system.out.print(count+” ”);

count++; }

• 1 2 3

• 1

  2

  3

• 111

• 3

Predict the output of the following code fragment

int sum = 14;

if ( sum < 20 )

System.out.print("Under ");

else

System.out.print("Over ");

System.out.println("the limit.");

• Under

  the

  limit

• Over

  the

  limit

• Under the limit

• Over the limit

Construct the syntax to create an object from a class named Student.

• Student poli = void Student ();

• Student poli = new Poli ();

• Student poli = new Student ();

• Student poli = Student Poli;

Classify which statement that refers to constructor characteristic

• Cannot be the same name as class name.

• Must start with void keyword.

• Must have a return value.

• Special kind of method.

Predict the output of the following codesnippet if variable

a=10

if(a<=0)

{ if(a==0) {

System.out.println("1 "); }

else { System.out.println("2 "); }

} System.out.println("3 ");

• 1

• 12

• 123

• 3

Choose the TRUE statement for Do statement

• do statement executes the code of a loop at least once

• do statement does not get execute if condition is not matched in the first iteration

• do statement checks the condition at the beginning of the loop

• do statement executes the code more than once always

Select the keyword that used with the switch statement

• continue

• exit

• break

• do