3.3: Bounds check
- Page ID
- 49272
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The third aspect of an array index is the check for valid ranges and what happens when an invalid index is accessed. This is a very important point since the majority of computer worms and computer viruses attack by using invalid array bounds.
There are three options open:
- Most languages (Ada, PL/I, Pascal, Java, C#) will check the bounds and raise some error condition when an element is accessed which does not exist.
- A few languages (C, C++) will not check the bounds and return or set some arbitrary value when an element outside the valid range is accessed.
- Scripting languages often automatically expand the array when data is written to an index which was not valid until then.