Filter and map operations in Kafka - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to filter messages with value greater than 10.

Kafka

stream.filter(record -> record.value() [1] 10);

Drag options to blanks, or click blank then click option'

A>

B<=

C==

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' will filter the wrong records.

Using '==' will only keep records equal to 10.

The filter should keep records where the value is greater than 10, so we use the > operator.

2fill in blank

medium

Complete the code to map each record to its key.

Kafka

stream.map(record -> record.[1]());

Drag options to blanks, or click blank then click option'

Avalue

Btopic

Ctimestamp

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using value() returns the value, not the key.

Using timestamp() or topic() returns other info.

To get the key from a record, use the key() method.

3fill in blank

hard

Fix the error in the filter condition to keep records with even values.

Kafka

stream.filter(record -> record.value() [1] 2 == 0);

Drag options to blanks, or click blank then click option'

A/

B*

C%

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using division / instead of modulo %.

Using multiplication or addition operators.

The modulo operator % returns the remainder. To check even numbers, use value() % 2 == 0.

4fill in blank

hard

Fill both blanks to create a map of keys to values for records with values greater than 5.

Kafka

stream.filter(record -> record.value() [1] 5).map(record -> new KeyValue<>(record.[2](), record.value()));

Drag options to blanks, or click blank then click option'

A>

B<

Ckey

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' instead of '>' in the filter.

Using value() instead of key() for the key.

We filter records with values greater than 5 using >. Then we map to a KeyValue with the record's key and value.

5fill in blank

hard

Fill all three blanks to filter records with values less than 20, map to uppercase keys, and keep values.

Kafka

stream.filter(record -> record.value() [1] 20).map(record -> new KeyValue<>(record.[2]().[3](), record.value()));

Drag options to blanks, or click blank then click option'

A<

Bvalue

CtoUpperCase

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' instead of '<' in the filter.

Using value() instead of key() for the key.

Not calling toUpperCase() on the key.

We filter records with values less than 20 using <. Then map to a KeyValue with the uppercase key and the value.