1.1 Arrays in Data Structure | Declaration, Initialization,
Memory representation
Lectures CS IT
Understanding Memory and Arrays in
Programming
In programming, memory is essentially a long tape of bytes, with
each byte containing 8 bits. This can be extended to both sides,
making it open-ended. To understand the need for arrays, we
need to examine how areas can be declared, initialized, and
represented in memory.
Storing Values in Memory
To store a value in memory, we need to know how much space
will be allocated for it. For example, the data type int typically
takes up 4 bytes to store an integer. The number 5 would need to
be converted to binary, which is 32 bits or 4 bytes. In traditional
compilers, we generally take 2 or 4 bytes to be the data type for
storing numbers. So, if we were storing an integer, it would take
up 2-4 bytes in memory.
The memory manager would allocate some memory for storing a
variable, and the value stored in memory would be represented
in binary. For example, the value stored in a variable could be 5,
which would be represented as 101 in binary.
Using Arrays
An array is a collection of more than one element of the same
datatype. For example, an array of characters would be of the
data type char, and an array of integers would be of the data
type int. The number of elements in an array is determined by
the size of the array.
To declare an array in programming, we use a specific syntax. In
C language, for example, we would write:
int n;
to declare an integer variable. To declare an array, we would use:
Memory representation
Lectures CS IT
Understanding Memory and Arrays in
Programming
In programming, memory is essentially a long tape of bytes, with
each byte containing 8 bits. This can be extended to both sides,
making it open-ended. To understand the need for arrays, we
need to examine how areas can be declared, initialized, and
represented in memory.
Storing Values in Memory
To store a value in memory, we need to know how much space
will be allocated for it. For example, the data type int typically
takes up 4 bytes to store an integer. The number 5 would need to
be converted to binary, which is 32 bits or 4 bytes. In traditional
compilers, we generally take 2 or 4 bytes to be the data type for
storing numbers. So, if we were storing an integer, it would take
up 2-4 bytes in memory.
The memory manager would allocate some memory for storing a
variable, and the value stored in memory would be represented
in binary. For example, the value stored in a variable could be 5,
which would be represented as 101 in binary.
Using Arrays
An array is a collection of more than one element of the same
datatype. For example, an array of characters would be of the
data type char, and an array of integers would be of the data
type int. The number of elements in an array is determined by
the size of the array.
To declare an array in programming, we use a specific syntax. In
C language, for example, we would write:
int n;
to declare an integer variable. To declare an array, we would use: