python chapter 2, 3
This symbol marks the beginning of a comment in Python. a. & b. * c. ** d. #
#
This operator performs division, but instead of returning the quotient it returns the remainder. a. % b. * c. ** d. /
%
This is an operator that raises a number to a power. a. % b.* c. ** d. /
**
This operator performs integer division. a. // b. % c. ** d. /
//
Which of the following statements will cause an error? a. x = 17 b. 17 = X C. X = 99999 d. X = '17'
17 = X
Which of the following is NOT a legal identifier? a. outrageouslyAndShockinglyLongRunon b. _42 c. _ d. lovePotionNumber9 e. 7thheaven
7thheaven
What types of relationships between values can you test with relational operators?
> greater than < less than >= greater than or equal to <= less than or equal to == equal to != not equal to
What is a flag variable?
A Boolean variable that when the flag value is true it means the condition exists, while a false value of the flag means the condition does not exist.
What values can you assign to a bool variable?
A bool variable can only store one of two possible values: True or False. Example: x = true; y = false
What is a compound Boolean expression?
A combination of two or more Boolean expressions using logical operators such as "and", ""or", and "not".
Which of the following is not true? a. An algorithm allows ambiguity. b. An algorithm, when carried out, must eventually stop. c. An algorithm, can be carried out by a human being.
An algorithm allows ambiguity.
Briefly describe how the "and" operator works.
An expression formed by the "and" operator is true only when both the 'first' and 'second' sub expressions are true. If the left sub expression is false then it will not check the right sub expression because the overall expression has already been determined as false, this is called "short cut evaluation".
Briefly describe how the "or" operator works.
An expression formed by the "or" operator is false only when both the 'first' and 'second' sub expressions are false. If the left sub expression is true then it will not check the right sub expression because the overall expression has already been determined as true, this is called "short cut evaluation".
A(n) _____ expression has a value of either true or false. a. binary b. decision c. unconditional d. Boolean
Boolean
What is a Boolean expression?
Boolean expressions check the truth of an expression, it checks whether the expression is true or false.
What is a decision structure?
Decision structures are control structures which provide a different set of instructions to be executed based on different choices made by the user.
How does a dual alternative decision structure work?
Dual alternative decision structure is a control structure with two possible paths of execution. The program will follow one path if condition equals true and another if condition equals false.
You need to test a condition and then execute one set of statements if the condition is true. If the condition is false, you need to execute a different set of statements. What structure will you use?
Dual alternative decision structure.
A program can be made of only one type of control structure. You cannot combine structures. T or F
False
A single alternative decision structure tests a condition and then takes one path if the condition is true, or another path if the condition is false. T or F
False
If you print a variable that has not been assigned a value, the number 0 will be displayed. T or F
False
Programmers must be careful not to make syntax errors when writing pseudocode programs. T or F
False
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. False and False
False
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. False and True
False
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. False or False
False
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. True and False
False
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. not True
False
Variable names can have spaces in them. T or F
False
You can write any program using only sequence structures. T or F
False
What does a professional programmer usually do first to gain an understanding of a problem?
First gain the requirement of the program for which it is being designed. Requirements include the task or goals which the program has to perform.
What is a flag and how does it work?
Flags are Boolean variables that indicate whether a specific condition exists or not. When the flag value is true it means the condition exists, while a false value of the flag means the condition does not exist.
What is the difference between floating-point division and integer division?
Floating point division, /, - returns the output in floating data type. It gives the result in decimal places. Integer division, //, - returns the output in integer value. It ignores the decimal place value.
Explain what is meant by the term "conditionally executed."
Is a set of statements that are executed only when a certain condition is true. If the condition is false they will not be executed. Also called a single alternative decision structure.
What is pseudocode?
It is an informal description of the algorithm.
Which of the following names in a program is equivalent to the name int? a. Int b. INT c. All of the above d. None of the above
None of the above
Computer programs typically perform what three steps?
Receiving of input Processing of input Producing output from received input
What is a single alternative decision structure?
Single alternative decision structure is a control structure that only provides one alternative path of execution. If the condition is true the alternative path is taken, if the condition is false the alternative path is skipped.
What is a control structure?
The logical design which is used to control or handle the execution order of statements.
Replace the underlines with the words in parentheses that follow: The ____ solves the ____ of a ____ by expressing an ____ in a ____ to make a ____ that can run on a ____. algorithm computer problems program programmer programming language user
The programmer solves the problems of a user by expressing an algorithm in a programming language to make a program that can run on a computer.
A compound Boolean expression created with the "and" operator is true only when both subexpressions are true. T or F
True
A decision structure can be nested inside another decision structure. T or F
True
In Python the first character of a variable name cannot be a number. T or F
True
In a math expression, multiplication and division takes place before addition and subtraction. T or F
True
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. False or True
True
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. True and True
True
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. True or False
True
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. True or True
True
The following shows a combination of the values true and false connected by a logical operator. Indicate whether the result of such a combination is true or false. not False
True
When you write an if-else statement, under what circumstances do the statements that appear after the else clause execute?
When the if condition is false the program follows the else clause.
The character escape sequence to represent a double quote is:
\"
The character escape sequence to represent a single quote is:
\'
The character escape sequence to represent a backslash is:
\\
The character escape sequence to force the cursor to go to the next line is:
\n
The character escape sequence to force the cursor to advance forward to the next tab setting is:
\t
Which of the following IS a legal identifier? a. 5_And_10 b. Five_&_Ten c. ____________ d. LovePotion#9 e. "Hello World"
____________ Correct - Weird, but valid.
A(n) _______ is a set of well-defined logical steps that must be taken to perform a task. a. logarithm b. plan of action c. logic schedule d. algorithm
algorithm
A compound Boolean expression created with the _____ operator is true only if both of its subexpressions are true. a. and b. or c. not d. both
and
When determining whether a number is inside a range, which logical operator is it best to use?
and
Explain how short-circuit evaluation works with the "and" and "or" operators.
and operator short circuit - If the left sub expression is false then it will not check the right sub expression because the overall expression has already been determined as false. or operator short circuit - If the left sub expression is true then it will not check the right sub expression because the overall expression has already been determined as true.
A(n) _______ makes a variable reference a value in the computer's memory. a. variable declaration b. assignment statement c. math expression d. string literal
assignment statement
Short notes placed in different parts of a program explaining how those parts of the program work are called _______. a. comments b. reference manuals c. tutorials d. external documentation
comments
A _____ structure can execute a set of statements only under certain circumstances. a. sequence b. circumstantial c. decision d. Boolean
decision
A(n) _____ structure tests a condition and then takes one path if the condition is true, or another path if the condition is false. a. if statement b. single alternative decision c. dual alternative decision d. sequence
dual alternative decision
A string literal in Python must be enclosed in a. parentheses. b. single-quotes. c. double-quotes. d. either single-quotes or double-quotes.
either single-quotes or double-quotes
According to the behavior of integer division, when an integer is divided by an integer, the result will be a float.
false
Python uses the same symbols for the assignment operator as for the equality operator.
false
Short -circuit evaluation is only performed with the not operator.
false
Since a named constant is just a variable, it can change any time during a program's execution.
false
The Python language is not sensitive to block structuring of code.
false
The following statement will check to see if the turtle's pen color is 'green': if turtle.pencolor() = 'green'
false
python formats all floating-point numbers to two decimal places when outputting with the print statement
false
A _____ is a Boolean variable that signals when some condition exists in the program. a. flag b. signal c. sentinel d. siren
flag
Suppose the following statement is in a program: price = 99. 0. After this statement executes, the price variable will reference a value of this data type. a. int b. float c. currency d. str
float
If a math expression adds a float to an int, what will the data type of the result be?
float data type
This built-in function can be used to convert an int value to a float. a. int_to_float() b. float() c. convert ( ) d. int()
float()
A _______ is a diagram that graphically depicts the steps that take place in a program. a. flowchart b. step chart c. code graph d. program graph
flowchart
Of the following variable names, which is the best one for keeping track of whether a patient has a fever or not? a. temperature b. feverTest c. hasFever d. fever
hasFever
You use a(n) _____ statement to write a single alternative decision structure. a. test-jump b. if c. if-else d. if-call
if
You use a(n) _____ statement to write a dual alternative decision structure. a. test-jump b. if c. if-else d. if-call
if-else
What statement do you use in Python to write a dual alternative decision structure?
if..... else
This built-in function can be used to read input that has been typed on the keyboard. a. input() b. get_input() c. read_ input ( ) d. keyboard ( )
input()
A _______ error does not prevent the program from running, but causes it to produce incorrect results. a. syntax b. hardware c. logic d. fatal
logic
The purpose of testing a program with different combinations of data is to expose run-time and _______ errors.
logical
and, or, and not are _____ operators. a. relational b. logical c. conditional d. ternary
logical
Of the following variable names, which is the best one for keeping track of whether an integer might be prime or not? a. divisible b. isPrime c. mightBePrime d. number
mightBePrime
The _____ operator takes a Boolean expression as its operand and reverses its logical value. a. and b. or c. not d. either
not
In the expression 12 + 7, the values on the right and left of the + symbol are called a. operands b. operators c. arguments d. math expressions
operands
A compound Boolean expression created with the ____ operator is true if either of its subexpressions is true. a. and b. or c. not d. either
or
An informal language that has no syntax rules and is not meant to be compiled or executed is called _______. a. faux code b. pseudocode c. Python d. a flowchart
pseudocode
The symbols >, <, and == are all _____ operators. a. relational b. logical c. conditional d. ternary
relational
A _____ structure provides one alternative path of execution. a. sequence b. single alternative decision c. one path alternative d. single execution decision
single alternative decision
A _______ is a single function that the program must perform in order to satisfy the customer. a. task b. software requirement c. prerequisite d. predicate
software requirement
A _______ is a sequence of characters. a. char sequence b. character collection c. string d. text block
string
A flowchart is a tool used by programmers to design programs.
true
An action in a single alternative decision structure is performed only when the condition is true.
true
Decision structures are also known as selection structures.
true
Expressions that are tested by the if statement are called Boolean expressions.
true
In Python, print statements written on separate lines do not necessarily output on separate lines.
true
Nested decision statements are one way to test more than one condition.
true
Python allows programmers to break a statement into multiple lines
true
The following code snippet will change the turtle's pen size to 4 if it is presently less than 4: if turtle.pensize() < 4: turtle.pensize(4)
true
The if statement causes one or more statements to execute only when a Boolean expression is true.
true
When using the camelCase naming convention, the first word of the variable name is written in lowercase and the first characters of all subsequent words are written in uppercase.
true
A _____ is any hypothetical person using a program and providing input for it. a. designer b. user c. gumea p1g d. test subject
user
A _____ is a name that references a value in the computer's memory. a. variable b. register c. RAM slot d. byte
variable
A location in memory used for storing data and given a name in a computer program is called a _________ because the data in the location can be changed.
variable
