Which error occurs when trying to access memory that has not been allocated or that has been freed?

Which error occurs when trying to access memory that has not been allocated or that has been freed?

• A. Segmentation fault
• B. Null pointer exception
• C. Array index out of bounds
• D. Data type mismatch

Answer: (A)

A segmentation fault occurs when a program attempts to access a memory segment that it is not allowed to access. This can happen if a program tries to access memory that hasn't been allocated, meaning the program is attempting to read or write a section of memory that hasn’t been properly reserved for its use. Additionally, if a program attempts to access memory that has been freed, it can also lead to a segmentation fault because the memory is no longer valid for the program to utilize. In programming, especially in languages like C, memory management is crucial, and improper handling can easily lead to segmentation faults. These errors typically result in the immediate termination of the program, making debugging necessary to identify the exact line where the invalid memory access occurred. The other options represent different types of errors unrelated to memory access violations. A null pointer exception deals with referencing a null (uninitialized) pointer, which is different from accessing freed or unallocated memory. An array index out of bounds error occurs when trying to access an element outside the defined bounds of an array, but this does not directly relate to memory allocation. Lastly, a data type mismatch occurs when there is an attempt to use incompatible types in an operation, which is another distinct problem from memory access errors.

A segmentation fault occurs when a program attempts to access a memory segment that it is not allowed to access. This can happen if a program tries to access memory that hasn't been allocated, meaning the program is attempting to read or write a section of memory that hasn’t been properly reserved for its use. Additionally, if a program attempts to access memory that has been freed, it can also lead to a segmentation fault because the memory is no longer valid for the program to utilize.

In programming, especially in languages like C, memory management is crucial, and improper handling can easily lead to segmentation faults. These errors typically result in the immediate termination of the program, making debugging necessary to identify the exact line where the invalid memory access occurred.

The other options represent different types of errors unrelated to memory access violations. A null pointer exception deals with referencing a null (uninitialized) pointer, which is different from accessing freed or unallocated memory. An array index out of bounds error occurs when trying to access an element outside the defined bounds of an array, but this does not directly relate to memory allocation. Lastly, a data type mismatch occurs when there is an attempt to use incompatible types in an operation, which is another distinct problem from memory access errors.