AP Computer Science A Flashcards: Casting and Range of Variables
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What is a round-off error?
A round-off error occurs when an expression evaluates to a double that is more precise than can be stored. The result is rounded to the nearest representable value.
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What is a round-off error?
A round-off error occurs when an expression evaluates to a double that is more precise than can be stored. The result is rounded to the nearest representable value.
How does a round-off error affect the value of a `double` expression?
A round-off error changes the value of a double expression by rounding it to the closest value that can be accurately stored in the allotted memory.
What is the resulting value of the expression `(double) 25`?
The expression results in the double value 25.0. Casting an integer to a double adds a decimal component to represent it as a floating-point number.
What is a primary condition that limits the accuracy of expressions involving `double` values?
The accuracy of expressions is limited when a calculation produces a value that is more precise than can be stored in the allotted memory, resulting in a round-off error.
Define casting in the context of primitive types.
Casting is the development of code to convert primitive values to different primitive types within arithmetic expressions, such as using `(int)` to convert a `double` to an `int`.
What is the purpose of the casting operators `(int)` and `(double)`?
The casting operators `(int)` and `(double)` are used to explicitly convert a value from a double to an int, or vice versa, within an arithmetic expression.
What is the resulting value of the expression `(int) 8.9`?
The expression results in the integer value 8. When casting from a double to an int, the decimal part is truncated.
Under what condition does an integer expression evaluate to a value out of range?
An integer expression evaluates to a value out of its range when the calculated result is greater than the maximum, or less than the minimum, value that can be stored for that integer type.
How does integer overflow affect the result of a calculation?
Integer overflow produces an int value that is within the allowed range but is not the correct, expected mathematical result; it often 'wraps around' to the other end of the range.
What is integer overflow?
Integer overflow occurs when an expression evaluates to an int value outside of the allowed range. The result is an int value within the allowed range, but it is not the mathematically expected value.