Programming Quiz 1
How many bytes are in a kilobyte?
1024 bytes
The Java source file name must match what?
the public class name in the program
What are logical operators used for?
to create a compound Boolean expression
What causes a logic error?
when a program does not perform the way it was intended to
What are the logical operators in java?
&& and both conjunction - only true when both are true || or either disjunction - only false when both are false ! not opposite negation - true if false and false if true ^ exclusive or different - TF or FT operate with Boolean values and variables
What is the assignment operator in java?
(=) equal sign
How many bytes are in a megabyte?
1 million bytes
How many bytes are in a terabyte?
1 trillion bytes or 1,000 gigabytes
What do runtime errors do?
Cause a program to terminate abnormally
What is a high level language?
English-like and easy to learn and program Ex. Java
What does java do when evaluating an expression with values of mixed data types?
Java automatically converts the operands to appropriate types
Does the complier read comments?
No - java comments are ignored by the complier
What are variables used for?
To store data in a program
Does is matter what case (upper/lower) is used in java programs?
Yes, java programs are case sensitive
What are methods contained in?
a class
What is a bit?
short for binary digit takes the value of 0 or 1
How do you explicitly convert a data type to another data type?
use the type(value) notation Ex: int age = (int)(18.1);// age is assigned the value 18
What are the java operators that perform numeric operations?
+ addition - subtraction * multiplication / division % remainder
Which operators are used to increase or decrease a variable by 1?
++ increment operator -- decrement operator
What are the augment assignment operators java provides?
+= addition assignment -= subtraction assignment *= multiplication assignment /= division assignment %=remainder assignment
What are the syntax rules for identifiers?
- must start with a letter or underscore -cannot start with a digit -cannot be a reserved word -can be any length
What are the 6 selection statements?
- one-way if statements - two-way if statements - nested if statements - multi-way if-else statements -switch statements -conditional expressions
How many bytes are in a gigabyte?
1 billion bytes
What are the relational operators?
== equal to != not equal to >, <, >=, <=
What is a two-way if-else statement?
IF it is true - execute statement for the true statement Otherwise (ELSE) - execute statement for the false statement
When is a one-way if statement used?
If you want to execute only when a certain statement is true
What is a multi-way if else statement?
The if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.
What is a switch statement?
The switch statement is a multiway branch statement. It provides an easy way to dispatch execution to different parts of code based on the value of the expression Matches what it needs to and executes or if its N/a it goes default. Like a call-center
A variable declared in a method must be assigned a value before it can be used. True or False?
True
What do relational operators yield?
a Boolean value
What is the Central Processing Unit (CPU)?
a computer's brain it retrieves instructions from memory and executes them
What is a block comment?
a java comment enclosed between /* and */
What is a line comment?
a java comment preceded by two slashes (//)
What does a java program need to run?
a main method
What does every statement in java end with?
a semicolon (;)
What is a byte?
a sequence of 8 bits
What is machine language?
a set of primitive instructions built into the computer
What do boolean data types store?
a true or false value
What is a computer?
an electronic device for storing and processing data includes both hardware and software
What causes a syntax/compile error?
an error in the syntax
What is a memory unit?
an ordered sequences of bytes
What do java source files end with before and after compiled?
before: .java extension after: creates a bytecode file - .class extension
How is a named constant declared?
by using the keyword "final"
What are the four integer data types java provides?
byte short int long
What is type narrowing?
casting a variable of a data type with a large range to a variable of a data type with a small range must be performed explicitly
What is type widening?
casting a variable of a data type with a small range to a variable of a data type with a larger range can be performed automatically w/o explicit casting
What is software?
computer programs - the invisible instructions/code for computers to perform
What are the two floating-point types java provides?
float double
What does memory do?
holds the program instructions and the program data for the CPU to execute
What is a nested-if statement?
if the if is inside another if statement nested if statement will only be executed if the one above it is true Ex: if (i>k){ if (j>k){ System.out.print("i & j are greater than k) } } else { System.out.print("i is less than or equal to k) }
Why is memory volatile?
information stored in memory is lost when the power is turned off
What does the keyword "break" do in a switch statement?
it is optional and keeps the next case statement from being automatically executed
What does the keyword "default" do in a switch statement?
it is used to execute statements when none of the case values match with the argument provided to the switch statement
Assembly language is what level of programming language?
low-level
What are identifiers?
names for naming elements such as variables, constants, methods, classes, and packages in a program
How are programs and data stored?
permanently on storage devices and moved to memory when the computer actually uses them
What are selection statements used for?
programming with alternative courses of action -- allow the program to test several conditions