Array Access and Update at Index in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to access the element at index 2 in the array.

DSA C

int arr[] = {10, 20, 30, 40, 50};
int value = arr[[1]];
printf("%d\n", value);

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A2

B3

C1

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using index 3 or 4 which accesses wrong elements.

Forgetting that array indexes start at 0.

The index 2 accesses the third element in the array, which is 30.

2fill in blank

medium

Complete the code to update the element at index 1 to 100.

DSA C

int arr[] = {5, 10, 15, 20};
arr[[1]] = 100;
printf("%d\n", arr[1]);

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A2

B0

C3

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Updating the wrong index like 0 or 2.

Confusing index with the value.

Index 1 corresponds to the second element, which we update to 100.

3fill in blank

hard

Fix the error in the code to correctly update the last element of the array.

DSA C

int arr[] = {1, 2, 3, 4, 5};
int n = 5;
arr[[1]] = 50;
printf("%d\n", arr[4]);

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A5

Bn - 1

C4

Dn

Attempts:

3 left

💡 Hint

Common Mistakes

Using n as index which is out of bounds.

Using 5 as index which is invalid.

The last element is at index n - 1 because indexing starts at 0.

4fill in blank

hard

Fill both blanks to print the updated value at index 3 after setting it to 99.

DSA C

int arr[] = {7, 8, 9, 10, 11};
arr[[1]] = 99;
printf("%d\n", arr[[2]]);

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A3

B4

C2

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using different indexes for update and print.

Using out of range indexes.

Index 3 is updated to 99 and then printed from the same index.

5fill in blank

hard

Fill all three blanks to update the element at index 0 to 42, then print it.

DSA C

int arr[] = {0, 1, 2, 3};
arr[[1]] = [2];
printf("%d\n", arr[[3]]);

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A0

B42

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong index for update or print.

Using wrong value for update.

We update index 0 to 42 and then print the value at index 0.