Variables in C
While programming, we very often need to access the memory to read and write data.
The memory addresses are hexadecimal values.
So, it is very hard to keep track of hexadecimal values while programming.
To manipulate memory address easily, we can attach a variable name to the memory address.
So, it will be very easier to manipulate the memory address using a variable name rather than hexadecimal values.
In the above diagram, memory address 22fe4c has mapped with the variable name letter.
Using variable letter, we can easily manipulate the memory address 22fe4c.
Similarly, using variable letter2, we can easily manipulate the memory address 22fe4d.
Valid variable names in C
1. Variable name should start with letter(a-zA-Z) or underscore (_).
2.In variable name, no special characters allowed other than underscore (_).
3.Variables are case sensitive.
age and Age are different, since variable names are case sensitive.
4.Variable name can be constructed with digits and letters.
5.Variable name should not be a C keyword.Keywords are also called as reserved words.
int, main are reserved for special meaning. So, we should not declare keyword as a variable name.