Operators in C | sizeof

sizeof():

sizeof() helps to find size of a data type or a variable.

Syntax:
sizeof(variable/value);

Argument to sizeof() can be variable or value.

Example:

int a;
printf(“%d”,sizeof(int)); // o/p : 2 (Turboc3)
printf(“%d”,sizeof(a));// o/p : 2 (Turboc3)

printf(“%d”,sizeof(int)); // o/p : 4 (CodeBlocks)
printf(“%d”,sizeof(a));// o/p : 4 (CodeBlocks)

float x;
printf(“%d”,sizeof(float)); // o/p : 4
printf(“%d”,sizeof(x));// o/p : 4

/* 
size_1.cpp
*/
#include<stdio.h>
int main()
{
     int a;
     float b;
     char c;
     double d;
     printf("1. size of int %d\n",sizeof(a));
     printf("2. size of int %d\n",sizeof(int));
     printf("3. size of float %d\n",sizeof(b));
     printf("4. size of float %d\n",sizeof(float));
     printf("5. size of double %d\n",sizeof(d));
     printf("6. size of double %d\n",sizeof(double));
     printf("7. size of char %d\n",sizeof(c));
     printf("8. size of char %d\n",sizeof(char));
     return(0);
}

/* Output */
1. size of int 4
2. size of int 4
3. size of float 4
4. size of float 4
5. size of double 8
6. size of double 8
7. size of char 1
8. size of char 1

/* 
size_2.cpp
*/
#include<stdio.h>
int main()
{
     char n1[15]="abc";
     char n2[20]="hello";
     char n3[]="hello";
     printf("1. size =  %d\n",sizeof(3));
     printf("2. size =  %d\n",sizeof(3.5));
     printf("3. size =  %d\n",sizeof(34.656));
     printf("4. size =  %d\n",sizeof(34.65e6));
     printf("5. size =  %d\n",sizeof('A'));
     printf("6. size =  %d\n",sizeof('5'));
     printf("7. size =  %d\n",sizeof("abc"));
     printf("8. size =  %d\n",sizeof("Hello World"));
     printf("9. size =  %d\n",sizeof("abc 12"));
     printf("10. size =  %d\n",sizeof(n1));
     printf("11. size =  %d\n",sizeof(n2));
     printf("12. size =  %d\n",sizeof(n3));
     printf("13. size =  %d\n",sizeof(3.5f));
     printf("14. size =  %d\n",sizeof(34.65e6f));
     return(0);
}

/* Output */
1. size =  4
2. size =  8
3. size =  8
4. size =  8
5. size =  1
6. size =  1
7. size =  4
8. size =  12
9. size =  7
10. size =  15
11. size =  20
12. size =  6
13. size =  4
14. size =  4