Study Guide: JavaScript, Web Concepts, and Block Coding 2.0

Loops in programming are used to: A) repeat actions B) style elements C) add content D) create databases.

• repeat actions

• style elements

• add content

• create databases

Answer explanation

Loops in programming are primarily used to repeat actions multiple times, making them essential for tasks that require iteration. Therefore, the correct answer is A) repeat actions.

Which of the following is an example of a block coding platform?

• Scratch

• Python

• Java

• HTML

Answer explanation

Scratch is a block coding platform that allows users to create programs by snapping together code blocks visually. In contrast, Python, Java, and HTML are text-based programming languages.

What does an if-then block do?

• Runs code if a condition is false

• Runs code if a condition is true

• Runs code indefinitely

• Runs code based on user input

Answer explanation

An if-then block executes code only when a specified condition is true. This is fundamental in programming for controlling the flow of execution based on conditions.

Fill in the blank: An if-then-else block runs one action if the condition is true and another if ______.

• the condition is false

• the user inputs data

• the loop ends

• the program starts

Answer explanation

An if-then-else block executes one action when the condition is true and a different action when the condition is false. Therefore, the correct completion of the statement is 'the condition is false'.

Which block is used to run code if a condition is true?

• If-Then Block

• Loop Block

• Forever Loop

• Repeat Until Block

Answer explanation

The If-Then Block is specifically designed to execute code when a specified condition is true, making it the correct choice. Other options like Loop Block and Forever Loop are used for repeated actions, not conditional execution.

What are comparison operators used for?

• To store values

• To compare values

• To execute actions

• To define functions.

Answer explanation

Comparison operators are specifically designed to compare values, determining their relationships (e.g., equal to, greater than). This makes 'To compare values' the correct choice, as the other options do not accurately describe their function.

What does a wait block do?

• Starts a game

• Pauses execution

• Stores values

• Combines conditions

Answer explanation

A wait block is used to pause execution in a program, allowing for a delay before the next action occurs. This is essential for timing control in animations or game events.

Fill in the blank: A custom block is a user-defined function that ______ multiple blocks.

• A) separates

• B) groups

• C) deletes

• D) ignores

Answer explanation

A custom block is designed to organize and manage code efficiently. Therefore, it 'groups' multiple blocks together, making option B the correct choice, as it reflects the purpose of a custom block in programming.

Which of the following is an example of a custom block?

• wait 2 seconds

• set score to 0

• define moveForward

• when flag clicked

Answer explanation

The correct choice, 'define moveForward', is an example of a custom block because it allows users to create a new block with a specific function. The other options are standard commands or event triggers, not custom definitions.

Fill in the blank: Code efficiency involves writing code that is ______.

• slow

• efficient

• complex

• redundant

Answer explanation

Code efficiency means writing code that is efficient, which optimizes performance and resource usage. The correct choice, 'efficient', directly reflects this principle, while the other options do not align with the goal of efficient coding.