sizeof will return the number of bytes reserved for a variable or data type. The sizeof operator is a compile-time operator that returns an integer value. In other words since it is a compile time operator When the programmer uses the sizeof operator in a expression then the operator do not get compiled into executable code in the expression.
Syntax of this operator is
For instance if one wants to know the length of a data type it can be obtained by using sizeof operator as follows:
printf("%d n", sizeof(int));
This returns the size of integer which is generally 2.
Suppose we have a program like below
a= sizeof(10) / sizeof(b);
Then the result would be sizeof integer value generally would be 2 and sizeof float which would be generally 4. Therefore result would be 2/4 which gives result as 0.