Question

What does "array bounds checking" mean?

Short answer

Array bounds checking is a safety feature in certain programming languages that prevents any access to non-existing array elements. It ensures that a program can only access elements within the boundaries of an array, preventing errors or security issues that may arise from attempting to access non-existing elements. This helps maintain the integrity of the program, detect programming errors, and prevent unpredictable behavior or potential crashes.

Step-by-step solution

Define Array

An array is a data structure in programming languages that stores a fixed-size sequence of elements of the same type. The elements of an array can be accessed by their index, which indicates the position of the element in the array. Indices usually start at zero, so the first element is at index 0, the second element at index 1, and so on.

Explain Array Bounds Checking

Array bounds checking is a safety feature in certain programming languages (such as Java, Python, and Swift) that prevents any access to non-existing array elements. This means, if a program tries to access an element with an index that is outside the array's size, it generates an error or an exception instead of potentially using or modifying unintended memory locations.

Give an Example

Let's consider an example. Suppose an array has 5 elements with the indices 0, 1, 2, 3, and 4. If a programmer inadvertently tries to access the array with an index of 5 (which would be the 6th element, nonexistent in this case), the programming language with array bounds checking would detect this invalid access and raise an error.

Importance of Array Bounds Checking

Array bounds checking is important for multiple reasons: 1. It prevents the program from accessing or modifying memory locations that are not intended to be part of the array. 2. It helps detect programming errors that may have led to accessing nonexistent array elements. 3. Array bounds checking prevents unpredictable behavior or potential crashes caused by accessing memory locations dedicated to other parts of the program or system. In conclusion, "array bounds checking" is a method to ensure that a program can only access elements within the boundaries of an array, preventing errors or security issues that may arise from attempting to access non-existing elements.