The document discusses the sizeof operator in C/C++. It explains that sizeof returns the size of a data type or variable in integer format. It provides examples showing sizeof can be used with basic data types like char, int, float, and double to return their memory allocation sizes. The document also briefly mentions declaring variables, constants, and strings in C/C++.

1. Computer Programming
Structure of C/C++ Program
DIT Part 1
Lecture 5

2. Size of Operator
• Size of operator is used to calculate the size of
data type or variables.
• Size of operator can be nested.
• Size of operator will return the size in integer
format.
• Size of operator syntax looks more like a
function but it is considered as an operator in
c programming
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3. Size of Operator
When sizeof() is used with the data types such as int, float, char… etc it
simply return amount of memory is allocated to that data types.
Let see example:
#include<stdio.h>
int main()
{
printf("%dn",sizeof(char));
printf("%dn",sizeof(int));
printf("%dn",sizeof(float));
printf("%d", sizeof(double));
return 0;
}
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4. Declaring Variable
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5. Declaring Constant
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6. String
• Strings are actually one-dimensional array of
characters terminated by a null character '0'.
• Thus a null-terminated string contains the
characters that comprise the string followed by
a null.
• The following declaration and initialization create
a string consisting of the word "Hello".
• To hold the null character at the end of the array,
the size of the character array containing the
string is one more than the number of characters
in the word "Hello."
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7. String
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8. Assignment
– Increment (++).
– Decrement(--).