Knowledge quiz

It’s time to put what you’ve learned to the test, get 8 questions right to pass this week.

What does the “combine” block do?

Choose the correct answer.

If the input list contains words only, it automatically generates a sentence by inserting a space after each item of the input list and punctuation after the last item.

If the input list contains numbers only, it automatically adds these numbers and reports their sum.

It takes a function with two input slots and combines two consecutive inputs of the input list using this function, and then reports a list that is half the length of the original input list.

It takes a function with two input slots, combines all items of the input list using this function, and reports a single value.

What color has a pixel with the values 200, 200, 0, 255?

Choose the correct answer.

Yellow

Magenta

Green

Teal

Which block can be used to find out whether a value is part of a list?

Choose the correct answer.

_ contains _

is _ a _?

_ mod _

is _ empty?

Which of the following pixels is transparent?

Choose the correct answer.

255,255,255,255

255,0,255,0

0,0,0,255

0,255,0,255

How can you increase the volume of a recorded sound?

There are two correct answers.

By dividing each sample by a value > 1.

By increasing the frequency at which a sound is played back.

By multiplying each sample by a value > 1.

By increasing the amplitude of the samples.

Which of the following expressions will reduce the resolution of a color channel to a maximum of four different values when mapped over the pixels of a photo?

Choose the correct answer.

(floor of ( item _ of _ / 80 )) x 80

(floor of ( item _ of _ / 40 )) x 40

(floor of ( item _ of _ / 4 )) x 4

(floor of ( item _ of _ / 16 )) x 16

What does the “keep” block do?

Choose the correct answer.

It filters a list based on a condition and reports “true”, if the condition is true for at least one item and “false” if the condition is not met by any item.

It filters a list based on a condition and reports all items for which the condition is false.

It reports the first item of a list for which a specific condition is true.

It filters a list based on a condition and reports all items for which the condition is true.

How can you create an echo effect for a sound?

Choose the correct answer.

By averaging the value of a sample with one of the previous samples.

By multiplying the value of a sample with one of the next samples.

By duplicating each sample in the sample list.

By adding a default value to each sample in the sample list.

What does the “map” block do?

Choose the correct answer.

It applies a function on every element of a list and reports a new list containing all results.

It applies a predicate on every element of a list and reports a new list containing only those elements for which the predicate was true.

It combines all elements of a list in a single value using a function with two input slots.

It applies a predicate on every element of a list and reports the first element for which the predicate becomes true.

10.

How can you create snapshots in Snap!?

There are two correct answers.

By using the “snapshot” block from the Operators category.

By using the Webcam feature on the Costumes tab.

By right clicking a sprite and selecting Webcam from its context menu.

By choosing the snap option of the “video _ on _” reporter block from the Sensing category.