How to use the sizeof function in the C language?

In the C language, sizeof is an operator used to obtain the size of a variable or data type in bytes.

1. To obtain the size of a variable, you can use the sizeof operator with the variable name as its operand. For example,
2. int num;
   size_t size = sizeof(num);
   printf(“The size of variable num is: %zu bytes\n”, size);
3. To obtain the size of a data type, you can use the data type as an operand for the sizeof operator. For example,
4. Declare a variable called size to store the size of an integer data type, and then print out the size in bytes of the int type using the printf function.

It is worth noting that the sizeof operator returns a result of type size_t, which is an unsigned integer type. You can use the %zu format specifier to print values of type size_t.