A.P. Computer Science Course Unit 3

What is a variable?

An abstraction inside a program that can hold a value.

What are the benefits of using meaningful variable names?

They help with the readability of program code and understanding of represented values.

What is a data type?

A classification that specifies which type of value a variable can hold, such as numbers, Booleans, lists, and strings.

What is an array?

A systematic arrangement of objects usually in rows and columns, organized under a single name with distinct indexes.

What does variable declaration mean?

The process of creating a variable in the program before it can be used.

What is a local variable?

A variable that can only be accessed inside the specific code block where it was created.

What is a global variable?

A variable that can be accessed throughout the entire program.

What is the assignment operator?

An operator that allows a program to change the value represented by a variable.

What does 'null variable' refer to?

A variable that has no assigned value and serves as a placeholder for future data.

What is a list?

An ordered sequence of elements where each element has a unique index.

What is the difference between weakly typed and strongly typed languages?

In weakly typed languages, the data type is determined by the value, whereas in strongly typed languages, the data type must be explicitly defined.

What is algorithm sequencing?

The arrangement of steps in the order they are to be executed.

Define a selection in programming.

A structure that executes different parts of the code based on a Boolean condition.

What is iteration in programming?

A repetition of a set of instructions or statements in a program until a specified condition is met.

What is an object in programming?

A built-in function with a collection of properties and methods.

How does a procedure in programming function?

A named group of programming instructions that can take parameters and return values.

What is the difference between a decision problem and an optimization problem?

A decision problem has a yes/no answer, while an optimization problem seeks the best solution among many.

What is a heuristic?

An approach to a problem that is not guaranteed to be optimal but provides a practical solution.

What is an undecidable problem?

A problem for which no algorithm can be constructed to always provide a correct yes/no answer.

What is a binary search algorithm?

An algorithm that starts in the middle of a sorted dataset and eliminates half of the data in each step to find a desired value.

What is the purpose of simulations in programming?

To mimic real-world events, allowing investigation of phenomena without real-world constraints.