Java Tutorial Blog

SCJP 1.4 Mock Exam – 20







Mock Exam – Arrays
























Q1
Which of the following are valid array construction?

A1
int a[] = new int[];

A2
int a[] = new int[10];

A3
int a[10] = new int[];

A4
int a[] = new a[10];

























Q2
Which of the following are valid array initialization?

A1
new int[] = {1,2,3,4};

A2
new int[10] = {1,2,3,4};

A3
new int[] = 1,2,3,4;

A4
new int[] = [1,2,3,4];

























Q3
public class Test3{

    public static void main(String args[]){

         int arr[] = new
int[10];

         int i = 5;

         arr[i++] = ++i+i++;

        
System.out.print(arr[5]+”:”+arr[6]);

     }

}

What will be the output?

A1
14:0

A2
0:14

A3
0:0

A4
Compiler Error

























Q4
public class Test4{

     public static void main(String args[]){

          int arr[] =
new int[10];

          int i = 5;

          arr[i++] =
i+++i++;

         
System.out.print(arr[5]+”:”+arr[6]);

     }

}

What will be the output?

A1
13:0

A2
14:0

A3
0:14

A4
0:13

























Q5
public class Test5{

    static Boolean bl[] = new Boolean[5];

    public static void main(String args[]){

        
System.out.println(bl[0]);

    }

}

What will be the output?

A1
null

A2
false

A3
true

A4
Compiler Error





























Q6
Which of the following are valid array declarations?

A1
String[][] a1 = String[20][20];

A2
String[][] a2 = new String[20,20];

A3
String[][] a3 = new String[20][20];

A4
String a4[][] = new String[20][20];

A5
String[] a5[] = new String[20][20];

























Q7
Which of the following code correctly creates an array of

four initialized string objects?.

A1
 String players[] = new String[4];

A2
String players[] = {“”,””,””,””};

A3
String players[];


players = new String[4];

A4
None of the above.

























Q8
char[] c = new char[100];


what is the value of c[50]?


 

A1
50

A2
49

A3
‘\u0000’

A4
‘\u0020’

























Q9
 which of the following are valid arrays?

A1
new float[10]={1,2};

A2
new float[]={1,2};

A3
new float={1,2};

A4
none of the above

























Q10
public class Test10{

    public void method(int arr[]){

        arr[0] =
10;

    }

    public static void main(String[] args){

        int[] small
= {1,2,3};

        Test10 t=
new Test10();

       
t.method(small);

       
System.out.println(small[0]);

    }

}

 what will be the output?

A1
0

A2
1

A3
0

A4
none of the above






Answers











































1
 A2)int a[] = new int[10];

2
A1)new int[] = {1,2,3,4};

3
A1)14:0

4
A1)13:0

5
A1)null

6
A3 : String[][] a3 = new String[20][20];

A4 : String a4[][] = new String[20][20];

A5 : String[] a5[] = new String[20][20];

7
A2 : String players[] = {“”,””,””,””};

8
c) ‘\u0000’

9
b)new float[]={1,2};

10
10