Unit 1 Exam CS Principles

Why do we write comments?

To explain code and make it easier for humans to read.

How do we write comments?

Use # in Python to write a single-line comment.

What is a variable?

A named storage location that holds a value.

How do we format a variable to indicate that it is a constant?

Write the variable name in ALL CAPS.

Why is it useful to declare some variables as constants?

It makes the code clearer and prevents accidental changes.

What does this symbol (+) do when between two numbers?

It adds the numbers.

What does this symbol (+) do when between two strings?

It concatenates (joins) the strings.

What does this symbol (+) do when between a number and a string?

It causes an error because you can't add them directly.

What does the following code do: print("My favorite number is ", end='') print(9)

It prints My favorite number is 9 on one line without a space after the first part.

What does the following code do: print("It is\nnice to\nsee you.")

It prints text on multiple lines: "It is" / "nice to" / "see you."

What does * do when applied to a string?

It repeats the string that many times.

What does str() do? When might you use it?

It converts data into a string. Use it when printing numbers with text.

What do int() and float() do? When might you use them?

int() converts to an integer, float() converts to a decimal. Use them for math operations.

What does the comma do in console output?

It separates items and adds a space between them when printed.

What does type() do?

It shows the data type of a value or variable.

What is the syntax for the input function?

input("Prompt message: ")

The randint() method - how does it work?

It returns a random integer between two specified numbers (inclusive).