Section 1
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What is the syntax of a language?
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Section 1
(50 cards)
What is the syntax of a language?
The rules that determine how words and symbols can be combined
Which of the following is a Java Primitive type?
boolean, int, double
What is debugging?
The process of determining the root cause of a problem and fixing it
_________ is crucial in program style
Consistency
Java was created by a development team led by James Gosling
true
The Java Development Kit (JDK) is a _________ environment
command-line
The int, long, and short data types both represent integers
true
Numeric primitive values in Java are signed.
true
Java programs cannot be run on a web page
false
Java performs automatic garbage collection
true
The end-of-line block style aligns opening and closing braces vertically
False, the end-of-line block style puts the opening brace at the end of the preceding line
Classes in the Java API are organized into packages
true
The Java Virtual machine is software
true
A multi-line comment begins with what?
/ and ends with /
Internally, uppercase and lowercase letters are treated the same
false, they are distinct
Full documentation about the Java API can be found online.
true
The println statement is a call to method
true
In a programming language, a syntactically valid statement has only one meaning
true
Which of the following is NOT a valid Java identifier
1stPlace
Which is not a valid variable declaration in Java
int first = true you can not assign a boolean value to an int variable
Which of the following will produce a syntax error?
Omitting a necessary semicolon in a program
Comments
Provide extra information for humans to read and is ignored by the compiler
Java source code cannot be executed directly by a computer
True, it must be translated
What is programming convention?
A guideline about a program style that makes code easier to read
What is syntax coloring?
Showing certain elements of program code in different colors
Java is an object-oriented programming language
true
What software tool is used to translate Java source code into Java Bytecode
compiler
A Java comment cannot appear on a line that contains an executable statement
false, it can be put after the code to help explain that line
The float -
represents floating point values
Which of the following identifiers follows the convention for naming Java variables
totalValue
Characters in Java are represented by what?
Unicode character set
Sun created Java and was then bought by Oracle
true
A typical Java compiler produces which type of output?
Java bytecode
Which of the following will produce a runtime error?
Dividing by zero
What issue must be addressed when printing a long character strip?
A character string literal cannot span across multiple lines
The main method of a Java program must have which of the following method headers?
public static void main(String[] args)
What are the two categories of data types in Java
Primitive data and object references
System.out.print("Total: " + 100 20);
Total: 10020
What does the import statement do?
Identifies the package in which a class can be found
What is a natural language?
A language that humans use to communicate, such as English
Difference between print and println
print- whatever is printed next will be on the same line as what was printed previosly println- moves statement to the next line
Java is a general-purpose programming language
true
Which is true?
The body of a Java method is enclosed in curly braces
What output is produced? System.out.println(15 + 30);
45
How many primitive data types are there?
8
If the computer produces errors, it will not generate an executable version of the program
true
The Java compiler requires all indentation levels to be four spaces
False
The slogan "Write Once, Run Anywhere" is used to promote what?
Java's cross platform benefits
Using the Java API in a program is rare
false
What is the Java API/
A large library of classes
Section 2
(50 cards)
An import statement should be written inside a class but before any methods.
true, it should be written above the class
The first parameter to printf is
the format string
What is the result 43 % 5
3
An import statement tells the compiler which class you're referring to in a program.
true
If the current value of the integer variable num1 is 2 and the current value of the double variable num2 is 3.0, what value will be stored in num2 after the following line of code is executed? num2 /= num1 * num2
0.5 2*3.0=6.0 3.0/6.0=0.5
If both operands to the remainder operator (%) are positive, a divisor of n will produce a result in the range 1 to n
False, range is 0 to n-1
Two classes can have the same name if they are in different packages.
true
If the current value of the integer variable count is 2, what value will be stored in count after the following line of code is executed? count += count * 3;
8 2+2*3= 8
What is the result of the expression Math.pow(3, 3)?
27
What will the result of 7 / 2
3
What is the result of the expression Math.floor(12.843)?
12
If either or both operands to the division operator are floating-point values, then the result will be a floating-point value
true
The byte data type represents a true or false value
false, true/false is a boolean
The field width in a printf format specifier determines the total number of characters to be used to print the value.
true
When reading input using a Scanner object, if the type of input does not match the expected type, the compiler will issue an error message.
False, this type of problem cannot be detected during compilation. It is a runtime error
What should you pass to the Scanner constructor if you want to create a Scanner object that reads input typed at the keyboard.
System.in
When reading input using a Scanner object, each input value must be on its own line.
False, depending on what types of values are being read, they might be on the same input line
A printf format specifier changes the value in
the corresponding parameter
If the current value of the integer variable num is 4, what value will be sorted in num after the following line of code is executed? num +=2
6
The expression count++ can stand as a statement on its own
True
Given the following declarations, which assignment statement would cause the compiler to issue an error? int num1 = 5; int num2 = 3500; double num3 = 7.29;
num2 = num3 A double value cannot be assigned to an integer variable without a cast
A printf format specifier of %.3f will print a floating-point value truncated to 3 decimal places.
False, the value is rounded
The assignment operator has higher precedence than the arithmetic operators
False, The assignment operators have the lowest precedence
The printf method accepts a variable number of parameters
true
A constant is created using what?
final modifier
In a program, a class must always be referred to using its fully qualified name.
false,
Which line of code is equivalent to the following? depth += 50 * offset;
depth = depth + (50 * offset);
The Math class contains that represent the value pi to several digits
true
If the current value of the integer variable size is 2, what value will stored in size after the following line of code is executed? size *= 3;
6
Which of the following identifiers follows the naming convention for a Java constant?
MAX_PENALTIES All caps for naming a convention
What happens to the current value of the integer variable size when the following statement is executed?
The current value is overwritten by the new value
A type cast does what?
A cast causes a value to be treated as another type only for the current expression
Any data point in Java can make....
A constant
The method of the Math class is
static
The next and nextLine methods of the Scanner class both read and return character strings.
true
The format method of the String class accepts the same parameters as the printf method. True
true, same format but does not print
The Math.PI constant represents pi to 15 decimal places
true
If the variable num contains a positive integer, what are the only two possible results of the expression?
0 and 1
What value is assigned to the integer variable num by the following statement if the current value of num is 4? num = num * 2;
4
An entire package can be imported using one import statement
true, using the * wildcard character
The expression x^y raises the value x to the power y
False, use Math.pow(x,y)
Which of the following is NOT a constant declared in Java API
conversions.KILOMETERS_PER_mile Math.PI Math.E Integer.MAX_VALUE
The string class is a part of what package?
java.lang
A widening conversion converts a primitive value to a larger primitive type
True
A runtime error occurs when a printf field width is insufficient to display a value.
true
A static import let's you refer to a static method without using its class name.
true
The classes of the java.util package are automatically imported into every Java program.
false, only package automatically imported is java.lang
Constants make maintenance tasks easier
true
By default, what characters are used to separate input tokens when reading input using a Scanner object?
spaces, tabs, and newline characters
Suppose the integer variable hours contains a value that represents a number of hours. Which of the following expressions will compute how many 24-hour periods are represented by that value, without worrying about any leftover hours.
hours / 24
Section 3
(50 cards)
The relational operators can be used to put String objects in alphabetical order.
False
The not operator (!) requires two operands.
false, it only has one operand
If a String variable called pioneer contains the characters "Grace Murray Hopper", what is the result of the expression pioneer.length()?
19
If A is true and B is false, then the expression A || B is true. True
true, only one has to be true
What is a program's flow of control?
The order in which statements are executed
The arithmetic operators have a lower precedence than the relational operators.
false, other way around
What is the default flow of control through a method?
linear
What is ASCII
A subset of Unicode containing primarily English characters and basic symbols
After the following line of code is executed, the value stored in the variable num will be in what range? num = (int) (Math.random() * 25);
0 to 24
What is the output of the following statement? System.out.println("He said \"Avada Kedavra\"");
He said "Avada Kedavra"
If a String variable called address contains the characters "123 Main Street", what is the result of the expression address.indexOf('3')?
2, since string indexes start at 0, the character "3" is at index 2
The java keyword new is
an operator
What is the role of the seed value of a random number generator?
It is a number that is the basis of the calculated pseudorandom numbers
The condition of an if statement must be a boolean expression
true
What will happen if the variable total has the value 5 when the following code is executed? if (total > 8) System.out.println("collywobbles");
The word is not printed and processing continues
Given the following declaration, which expression would produce the substring "ledge"? String words = "Knowledge is power.";
words.substring(4,9);
Which statement would produce the following output? Eeny Meeny Miny Moe
is new line
\t is tab
A String method can be called through a string literal.
true
If the type of the expression in a return statement does not match the return type of the method, the compiler will issue an error message.
true, they must match
What output would be produced when the following code is executed? String state = "Mississippi"; System.out.println(state.replace("is", "was"));
Mwasswassippi
The result of a relational operator can be assigned to a boolean variable.
true
If gen refers to a Random object, the expression gen.nextInt(30) will produce a value in what range?
0 to 29 A call to nextInt(N) returns a value in the range 0 to N-1
What do the characters in a Unicode escape sequence represent?
the hexadecimal code for a particular unicode character
If gen refers to a Random object, which of the following expressions would produce a value in the range 1 to 10?
gen.nextInt(10) + 1
If a String variable called greeting contains the characters "hello", what does the expression greeting.toUpperCase() accomplish?
Returns a new string containing the characters "HELLO"
What operator is used to perform string concatenation in Java?
+
The unicode character set represents over 65,000 characters
true
A String object cannot be created using the new operator.
false, you can use the new operator, but often a string literal will suffice
Java uses the Unicode character set to represent characters.
true
If A is false, then the B operand in the expression A || B is not evaluated.
false, if b is true than it is true
A method declaration includes parentheses after the method name, even if the method takes no parameters. True
true, that is how the compiler knows you are declaring a method
Which is not valid?
""
""
This is not valid because the double quotes inside the string literal must be represented using escape sequences
What technique is used to put Unicode characters and strings in order?
lexicographic ordering
If gen refers to a Random object, the expression gen.nextInt(12) - 2 will produce a value in what range?
-2 to 9
Which statement would produce the following output? "Oom Pah Pah Oom Pah Pah," that's how it goes.
use \" to print quotation marks
Attempting to follow a null reference will cause an exception to be thrown.
true
When a method is called, the type and value of each argument are included in parentheses.
false, the types of arguments are only included in the method declaration
A constructor of a class has the same name as the class
true
If A and B are both false, then the expression A && B is false. True
true, both have to be true
A character set is
the list of all characters used by a programming language
An if statement affects a program's flow of control.
true, the condition determines which statement is executed next
The exclusive or operator (^) produces results that are opposite to the regular or operator (||).
false, the only difference is when both operands are true
An assignment statement affects a program's flow of control.
false, an assignment statement does not determine which statement is executed next
The return type of a method must either be a Java primitive type or void.
False, a method could also return an object
An object must be created when its object reference variable is declared.
false, those can be separate activities
The less than operator (<) should not be used to compare floating-point values.
false,
A variable can be declared inside the body of a method.
true, such variables are called local data
A method that has a return type of void does not have to have a return statement.
true
It is usually not a good idea to explicitly return a true or false literal value in a method that returns a boolean value.
true, it is better to return the boolean expression
If gen refers to a Random object, the expression gen.nextInt(10) + 5 will produce a value in what range?
5 to 14 If they initial range is 0 to 9, then it is shifted to 5 to 14
Section 4
(13 cards)