Common array operations - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an integer array of size 5.

C

int arr[[1]];

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A5

B10

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using zero as the size, which is invalid.

Forgetting to specify the size.

The code declares an integer array named arr with 5 elements.

2fill in blank

medium

Complete the code to access the third element of the array.

C

int value = arr[[1]];

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A1

B0

C3

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3 instead of 2 for the third element index.

Using 1 which is the second element.

Array indexes start at 0, so the third element is at index 2.

3fill in blank

hard

Fix the error in the loop to print all elements of the array of size 4.

C

for(int i = 0; i < [1]; i++) {
    printf("%d\n", arr[i]);
}

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

A4

B3

C5

D6

Attempts:

3 left

💡 Hint

Common Mistakes

Using 5 causes out-of-bounds access.

Using 3 misses the last element.

The loop should run while i is less than the array size, which is 4.

4fill in blank

hard

Fill both blanks to create a loop that sums all elements in an array named nums of size 6.

C

int sum = 0;
for(int [1] = 0; [1] < [2]; [1]++) {
    sum += nums[[1]];
}

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

Ai

B6

Cn

Dj

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not declared in the loop.

Using a wrong loop limit causing out-of-bounds access.

Variable i is commonly used as a loop counter. The loop runs while i < 6 to cover all elements.

5fill in blank

hard

Fill both blanks to declare an array, initialize it, and print its first element.

C

[1] arr[3] = {1, 2, 3};
printf("%d\n", [2]);

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

Aint

Carr[0]

Dfloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using different types for declaration and initialization.

Trying to print the whole array instead of one element.

The array is declared as int arr[3], initialized with values, and the first element arr[0] is printed.