Pointer and Array in C Programming Language

Pointer and Array

  • pointer and array are two variables that are used in a similar manner, they are both used to connect data and address.
  • despite their similar purpose, they have notable differences.
    • pointer, by definition, store the address of another variable. They take different addresses as value.
    • array, on the other hand, saves data in a structure to be accessed individually or as a group. All the elements are homogeneous, can be non sequential, and have fixed addresses
  • pointer syntax :<type> *ptr_name
    • example: ptr=i; *ptr=5. This means that i=5
    • pointer to pointer: ptr=i; ptr_ptr=ptr.
      • *ptr=5. This means that i=5
      • **ptr_ptr=9. This means that i=9 or *ptr=9
  • array syntax : <type> array_value[value_dim];
  • This consists of a type, identifier, operator, and dimensional value
    • example: int A[5]; this means that the array has 5 elements
  • array can also be initialized without dimensional value declarations
    • example: int A[]; {1,2,3,4}; this means the array has 4 elements
    • example: int A[5]; {1,2,3,4}; this means the array has 5 elements with 4 declared.
  • array can also be two dimensional and three dimensional
    • example: int A[2][2]; two dimensional
    • example: int A[2][2][2]; three dimensional
  • array and pointer can be combined to create an array of pointers

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