D278 Study QUESTIONS AND VERIFIED SOLUTIONS
What is the purpose of a variable? (L2) -✔✔To store data in a named memory location that
can be used and changed during program execution. How do you save a value to a
variable? (L2) -✔✔By using the assignment operator (=), e.g., x = 5 stores the value 5 in
variable x. What is a programming expression? (L2) -✔✔A combination of variables, values,
and operators that evaluates to a single result. What is an identifier? (L2) -✔✔The name
used to identify a variable, function, or other element in code. What constitutes a valid
identifier? (L2) -✔✔A valid identifier starts with a letter or underscore, followed by letters,
digits, or underscores; it cannot be a keyword. What is a literal? (L2) -✔✔A literal is a fixed
value written directly in code, like 5, 'A', or "hello". What is an operator? (L2) -✔✔An
operator is a symbol that performs an action on one or more operands, such as +, -, or *.
What precedence rules does programming use? (L2) -✔✔Operators follow specific
precedence rules; for example, multiplication and division are evaluated before addition
and subtraction. How does an integer differ from a float? (L2) -✔✔An integer is a whole
number with no decimal, while a float is a number that includes a decimal point. What
happens if you divide two integers? A integer and float? (L2) -✔✔Dividing two integers gives
a float. Dividing an integer by a float also gives a float. What happens if you divide a
nonzero floating point number by zero? (L2) -✔✔It results in positive or negative infinity, or
an error, depending on the programming language. How do you convert an item's type? (L2)
-✔✔By using type casting functions like int(), float(), or str() to convert between types.
What does the modulo operator do? (L2) -✔✔It returns the remainder of a division, e.g.,
7 % 3 equals 1. What is the difference in a variable and a constant? (L2) -✔✔A variable's
value can change; a constant's value stays the same throughout the program. How does
an array work? (L2) -✔✔An array stores multiple values of the same type in a single,
indexed collection. What does index reference? (L2) -✔✔An index references the position
of an element in an array, starting at 0. What is the purpose of each different data type?
(L2) -✔✔Different data types (int, float, char, string, etc.) define the kind of data a variable
can hold and how it's used in operations. How does a branch differ from a loop? (L3) -✔✔A
branch chooses between actions once; a loop repeats actions while a condition is true.
How does an if-else branch work? (L3) -✔✔It checks a condition; if true, one block runs,
else another block runs. What does the equality operator do? Does it work for all data
types? (L3) -✔✔It checks if two values are equal (==); it works for most data types but may
behave differently with complex types. What are the four relational operators? (L3) -✔✔<
(less than), > (greater than), <= (less than or equal), >= (greater than or equal). What are the
What is the purpose of a variable? (L2) -✔✔To store data in a named memory location that
can be used and changed during program execution. How do you save a value to a
variable? (L2) -✔✔By using the assignment operator (=), e.g., x = 5 stores the value 5 in
variable x. What is a programming expression? (L2) -✔✔A combination of variables, values,
and operators that evaluates to a single result. What is an identifier? (L2) -✔✔The name
used to identify a variable, function, or other element in code. What constitutes a valid
identifier? (L2) -✔✔A valid identifier starts with a letter or underscore, followed by letters,
digits, or underscores; it cannot be a keyword. What is a literal? (L2) -✔✔A literal is a fixed
value written directly in code, like 5, 'A', or "hello". What is an operator? (L2) -✔✔An
operator is a symbol that performs an action on one or more operands, such as +, -, or *.
What precedence rules does programming use? (L2) -✔✔Operators follow specific
precedence rules; for example, multiplication and division are evaluated before addition
and subtraction. How does an integer differ from a float? (L2) -✔✔An integer is a whole
number with no decimal, while a float is a number that includes a decimal point. What
happens if you divide two integers? A integer and float? (L2) -✔✔Dividing two integers gives
a float. Dividing an integer by a float also gives a float. What happens if you divide a
nonzero floating point number by zero? (L2) -✔✔It results in positive or negative infinity, or
an error, depending on the programming language. How do you convert an item's type? (L2)
-✔✔By using type casting functions like int(), float(), or str() to convert between types.
What does the modulo operator do? (L2) -✔✔It returns the remainder of a division, e.g.,
7 % 3 equals 1. What is the difference in a variable and a constant? (L2) -✔✔A variable's
value can change; a constant's value stays the same throughout the program. How does
an array work? (L2) -✔✔An array stores multiple values of the same type in a single,
indexed collection. What does index reference? (L2) -✔✔An index references the position
of an element in an array, starting at 0. What is the purpose of each different data type?
(L2) -✔✔Different data types (int, float, char, string, etc.) define the kind of data a variable
can hold and how it's used in operations. How does a branch differ from a loop? (L3) -✔✔A
branch chooses between actions once; a loop repeats actions while a condition is true.
How does an if-else branch work? (L3) -✔✔It checks a condition; if true, one block runs,
else another block runs. What does the equality operator do? Does it work for all data
types? (L3) -✔✔It checks if two values are equal (==); it works for most data types but may
behave differently with complex types. What are the four relational operators? (L3) -✔✔<
(less than), > (greater than), <= (less than or equal), >= (greater than or equal). What are the
