Deleting map entries in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to delete the key "apple" from the map.

Go

m := map[string]int{"apple": 5, "banana": 3}
delete(m, [1])

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

A"banana"

B"apple"

C"orange"

D"grape"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a key that does not exist in the map.

Forgetting to put the key in quotes.

The delete function removes the specified key from the map. Here, we delete the key "apple".

2fill in blank

medium

Complete the code to delete the key stored in variable key from the map.

Go

m := map[string]int{"cat": 1, "dog": 2}
key := "dog"
delete(m, [1])

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

Am

B"dog"

C"cat"

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Putting the variable name in quotes, which deletes a literal string key.

Passing the whole map instead of the key.

To delete a key stored in a variable, pass the variable name to delete. Here, key holds "dog".

3fill in blank

hard

Fix the error in the code to delete the key "blue" from the map.

Go

colors := map[string]string{"red": "#FF0000", "blue": "#0000FF"}
delete([1], "blue")

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

Acolor

Bcolors["blue"]

Ccolors

Dcolors[blue]

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a map element instead of the map variable.

Using an undefined variable name.

The delete function requires the map variable as the first argument. Here, the map is colors.

4fill in blank

hard

Fill both blanks to delete keys from the map only if they exist.

Go

m := map[string]int{"x": 10, "y": 20}
if _, ok := m[[1]]; ok {
    delete(m, [2])
}

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

A"x"

B"y"

C"z"

D"w"

Attempts:

3 left

💡 Hint

Common Mistakes

Using different keys in the check and delete.

Checking a key that does not exist.

We check if key "x" exists, then delete it. Both blanks use the same key "x".

5fill in blank

hard

Fill all three blanks to delete keys from the map only if their values are zero.

Go

m := map[string]int{"a": 0, "b": 1, "c": 0}
for k, v := range m {
    if v == [1] {
        delete([2], [3])
    }
}

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

A1

Bm

Ck

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing to 1 instead of 0.

Deleting from a wrong variable.

Using a string "k" instead of the variable k.

We delete keys whose value is zero. So, compare v == 0, delete from map m, key k.