What is pointer in computer language?

Answer 1

A pointer is a variable, much like any other variable, but one that contains a value that is interpreted as a memory address. The variable is said to "point" at that address. In 32-bit systems, the variable is 4-bytes in length. In 64-bit systems it is 8-bytes in length. If the value is zero the pointer is said to be NULL -- it doesn't point anywhere. Any other value denotes the pointer is pointing at a memory location. The type of pointer determines how it treats the memory it is pointing at. For instance, an int pointer treats the memory location as if it contained an integer -- regardless of its actual type. We can access the memory location itself by using the indirection operator (-->). Providing the pointer is the correct type for the object stored in that memory, we can work with the object just as if we had a direct reference to the object.

Pointers are extremely powerful. By altering the value stored in the pointer, the pointer can be made to point at any memory location -- including other pointer variables, objects and values, even functions. Pointers also allow us to pass memory locations to functions, in much the same way as we can pass values to functions. And like all other primitives, we can use simple mathematics to adjust a pointer's value, such as increment and decrement, allowing the pointer to "roam" through a series of memory locations.