CompSciFinalExam
Identify all Java code elements below that are related to the conditional building block in a Java program
&& switch if, else, else if
What syntax do we use to indicate a multi-line comment in Java?
/*
What syntax do we use to indicate a 1 line comment in Java?
//
How many times does the print occur? boolean valid = false; String today = "Wednesday"; int a = 5; while (!valid) { if (today.equals("Wednesday")) { valid = true; continue; } a++; System.out.println(a); }
0
What is in variable a, rounded to 2 decimal places, after completing the following? double a = 89%3;
2.0
What value is in b after completing the following Java syntax? int a = 5;int b = a++ * ++a;
30
What value is in a after completing the following Java syntax? int a = 5;int b = ++a * a--;
5
Which of the following allows me to expand or contract storage without fully replacing?
ArrayList
What data type do we rely on to consider alternate execution paths inside Java programs?
BOOLEAN
Complete Java syntax below to declare a variable of type character named letter, and assign the value A. [ fill this in ] letter = 'A';
Char
For a variable nums that represents an integer array, mark all that apply for nums.
Default value of elements is 0 and nums is a reference variable
Scanner aligns with which of the programming building blocks?
Input
When we run Java code in Eclipse, the .java file is converted to a stream of 0's and 1's. What do we call the interface layer that allows the resulting binary code to run on any computer, regardless of operating system?
JVM
Complete Java syntax to convert String "5" to an appropriate numeric value and store it invariable num. long num = [ fill this in ]("5");
Long.parseLong("5")
Which of the following Java elements align with the expressions building block?
Math.PI * / %
I ran the following Java code. Which of the following explains what occurred? short a = 120;short b = 75 - 25*3;if (b!=0 && a%b != 0) System.out.println("b is not divisor of a");
No error, no message, b is a divisor of a
What return type should we indicate when creating object constructor?
No return type
You have been asked to write code to swap the value at position 4 with the value 2 positions from end of String array vals. What data type should you declare for the temporary variable needed to complete this process?
String
I want to return formatted string output from a method that will contain a mix of strings, integer, floating point, and other values. For floating point values, I want to control the number of decimal places. For integer, I want to control the width. Which option below would be best solution?
String.format()
Complete Java syntax to convert boolean variable valid to String data type. String s = [ fill this in ](valid);
String.valueOf(valid);
Complete the Java syntax to extract the characters from string s String s = "Testing what you know"; System.out.println( ... ); DESIRED RESULT: ing wh
System.out.println(s.substring(4, 10) )
Correct the Java syntax in the last line below; currently I have an error. float a; 0double b = 2929.3939; a = b;
a =(float)b;
Complete the following Java syntax to evaluate the contents of variable a. The printshould only work when a is a multiple of 5. if ( ... ) { System.out.println(a); }
a%5==0
What do we call the values that are provided to a method as part of the method call?
aguremnets
How do we indicate code that is grouped together for a method, or a conditional, or a class in Java?
block
What type of variable is theNumber below? public class RandomGuess { public void genNumber() { for (int i=0; i < 10; i++) { int theNumber; Random num = new Random(); theNumber = num.nextInt(100) + 1; } } public String checkGuess(int guess) { ...
block variable
What Java syntax enables us to leave a loop, and not execute any remaining commands in the loop body?
break
Complete the Java syntax to retrieve the character t from String s String s = "One, two, again"; System.out.println( ... );
charAt(indexOf("t"));
What operation is performed by the second + in the following Java syntax? String s = "how is it going?" + 1 + 2 + 3;System.out.println(s);
concatenation
What Java syntax enables us to return to top of loop, complete iteration statement, and execute body of loop again?
continue
What type of loop would be most appropriate to identify the maximum value in the variable nums? int [] nums = {57, 34, 23, 15, 42, 87};
definite what version
What type of loop would be most appropriate to display the array nums in reverse? int [] nums = {57, 34, 23, 15, 42, 87};
definite, where version
Identify all Java code elements below that are related to the iteration building block in a Java program.
for (int i=0; i<10; i++) while (false) do ... while (true)
For which variables, would we typically create getters/setters?
instance variables
What value is displayed? String [] words = new String [4]; System.out.println(words[2]);
null
For a variable num that represents a local integer variable, mark all that apply
num is primitive variable
I am creating a class BankTeller that I will use to create multiple objects. There are several pieces of information each object should know about themselves. For example, name, window #, notary, experience level. What keyword should I include to ensure name is not visible outside the object? String name
private
If I do not want a class method or class variable to be visible outside the class, what keyword do I add to the declaration?
private
Which of the following are stored as 1D arrays inside a 2D array
rows
For a variable s that represents a String, mark all that apply specific to s.
s must be initialized,s can be converted to an array of characters
I have 2 String variables s1 and s2. Complete Java syntax to compare s1 and s2 to see if the contents are the same. s1[ fill this in ](s2);
s1.equals(s2);
This is a review question in preparation for final exam: What do we call the sort process by which an array is searched for the smallest or largest element, moves that element to front or back of array, and then continues with the next smallest or largest element? HINT: look at the deck on arrays, and then find sorting algorithms at back of deck.
selection
I am creating a class BankTeller that I will use to create multiple objects. There are several pieces of information each object should know about themselves. For example, name, window #, notary, experience level. I created a constructor that takes 4 parameters: name, window, notary, exper. When I try to initialize the instance variables, I get an error. What keyword should I include in order to address this error? private String name; private int window; private boolean notary; private String exper; public BankTeller(String name, int window, boolean notary, String exper) {
this
I am creating a class BankTeller that I will use to create multiple objects. Which of the following should I include in my class to provide means for objects to be printed once created?
toString method
Complete the Java syntax to retrieve the number 86 from the array nums int [] nums = {33, 45, 89, 72, 86}; System.out.println( ... );
nums[4];
What do we call the variables listed in a method definition that will contain copies of values provided when the method is called?
parameters
For a variable words that represents a String array, mark all that apply
words has a defined size and words is reference variable
Which of the following can I use to instantiate a Java object?
Random Scanner String
I completed the following Java syntax. Which of the following explain the result? String s1 = "This is a string"; String s2 = s1 + ""; System.out.println(s1==s2);
Strings stored in JVM are at different memory addresses
This is a review question in preparation for final exam: What do we call the sort process by which an array is traversed, swapping smallest or largest for every pair of elements, then repeating the process until no swaps are completed HINT: look at the deck on arrays, and then find sorting algorithms at back of deck.
bubble
I am creating a class BankTeller that I will use to create multiple objects. Which of the following should I include in my class to provide means for Java code to compare two objects of type BankTeller?
equals method
What do we call the process by which Java JVM reclaims memory when object is set to null?
garbage collection
Select all that apply.. I ran the following Java code. Which of the following explain the result? System.out.println('[' - 'c'); RESULT: -8
'[' occurs before 'c' char has Unicode equivalent for all characters
Correct the Java syntax to assign the value 5.8 to variable num float num = [ fill this in ];
(float)5.8;
What type of loop would be most appropriate to prompt for input, validate the input, display error messages, and continue until input is valid?
indefinite, one execution guaranteed
Complete the Java syntax to produce the desired result. String s = "TestIng sOmE mOrE";System.out.println("First e from end found at position");if (s.toLowerCase().contains("e")) { System.out.println( ... );}
indexof(e)