Array Index Out of Bounds

semantic

warning: array index 5 is past the end of the array

Description

Accessing an array element with an index that is outside the array's bounds.

Common Causes

• Using an index that is negative
• Using an index that is greater than or equal to the array's size
• Off-by-one errors in loop conditions

Example of Error

Error Code

int main() {
    int arr[5] = {1, 2, 3, 4, 5};
    printf("%d\n", arr[5]);  // Index out of bounds
    return 0;
}

Solution

Ensure array indices are within the valid range (0 to size-1).

Corrected Code

int main() {
    int arr[5] = {1, 2, 3, 4, 5};
    printf("%d\n", arr[4]);  // Last valid index is 4
    return 0;
}

Additional Tips

• Remember that array indices start at 0
• Use array size - 1 as the maximum index
• Consider using bounds checking in critical code