Question 1
Question
Which conditional statement would be best suited for determining the flow of code based on an int that may have a value between 1 and 10? The program must react differently for each value.
Question 2
Question
What Java code is used for declaring and initializing a null object?
Question 3
Question
Given the following code segment, what would be the output?
int value1 = 5;
int value2 = 7;
boolean bool1 = true;
boolean bool2 = false;
if (bool1 && (( value1 < value2 )|| bool2 ) && !(bool2)) {
System.out.println("Result set one");
}
else {
System.out.println("Result set two");
}
Answer
-
Result set one
-
Result set two
Question 4
Question
What is the output for the following Java code segment? The text in parentheses is meant to describe the whitespace and is not part of the output.
String fiveSpaces = " ";
String SCJA = "SCJA";
String lineToDisplay = "fiveSpaces + SCJA + fiveSpaces";
System.out.println(lineToDisplay.trim());
Answer
-
SCJA (no trailing and leading spaces)
-
SCJA (five leading and trailing spaces)
-
SCJA (four leading and trailing spaces)
-
fiveSpaces + SCJA + fiveSpaces
Question 5
Question
Given:
public class StringModifier {
public static void main (String[] args) {
String a = "Supercalifragilisticexpialidocious!";
String b = a.substring(x,y);
char [] c = {a.charAt(u), a.charAt(v)};
System.out.print(b + String.valueOf(c));
}
}
What integer declarations are needed to print the string fragile!?
Answer
-
int x = 8; int y = 14; int u = 2; int v =33;
-
int x = 10; int y = 16; int u = 4; int v =35;
-
int x = 8; int y = 15; int u = 5; int v =32;
-
int x = 9; int y = 15; int u = 3; int v =34;
Question 6
Question
You want to remove all leading and trailing whitespace from a string.Which method invocation will allow this to occur?
Question 7
Question
From highest precedence to lowest, which list of operators is ordered properly?
Answer
-
*, +, &&, =
-
*, &&, +, =
-
*, =, &&, +
-
+, *, &&, =
Question 8
Question
Given the following code that uses the modulus operator, what will be printed? System.out.print((24 % 8) + (10 % 7) + (100 % 99) + (38 % 6));
Question 9
Question
Given the following code segment testing the equality of two strings, what will be printed?
1. String string = "Dollar bill";
2. string.replace("Dollar bill","Silver dollar");
3. if ("Dollar bill".equals(string)) {
4. System.out.println ("I have a dollar bill.");
5. } else {
6. System.out.println ("I have a silver dollar.");
7. }
Question 10
Question
Which append declaration does not exist in Java 7?
Answer
-
public StringBuilder append (short s) {…}
-
public StringBuilder append (int i) {…}
-
public StringBuilder append (long l) {…}
-
public StringBuilder append (float f) {…}
-
public StringBuilder append (double d) {…}
Question 11
Question
Given:
System.out.println("A" + 1 + (1 + 1) + 1);
What will print?
Answer
-
A1111
-
A121
-
A13
-
A31
-
Compilation error
Question 12
Question
Given:
StringBuilder s = new StringBuilder ("magic");
s.append("al").replace(1, 3, "us").matches("musical");
System.out.println(s);
What will be printed to standard out?
Question 13
Question
Given:
boolean value = true;
System.out.print( true || (value=false));
System.out.println(", " + value);
What is printed to standard out?
Answer
-
true, true
-
true, false
-
false, true
-
false, false
Question 14
Question
Given:
String value1 = "null";
String value2 = "null";
System.out.println(value1.equalsIgnoreCase(value2));
What result will be seen upon compilation and/or execution?
Answer
-
A NullPointerException is thrown at runtime.
-
equalsIgnoreCase is not a valid method name and causes a compilation error.
-
"true" is printed to standard out.
-
"false" is printed to standard out.