Data Types in C
Data type:
- We need to specify the data type in variable declaration.
- Data type specifies, the type of data is allowed to store.
Data types are classified into:
Primitive types: In the above diagram primitive types are generalized. Primitive types sub classified as follows
Following table describes the data type with size, format specifier and limits:
Character data type: Char type is used to store alphabets, symbols and digits. We represents character with single quotes.
| #include <stdio.h> int main(){ char v1 = ‘a’; char v2 = ‘5’; char v3 = ‘$’; printf(“v1 value is : %c \n”, v1); printf(“v2 value is : %c \n”, v2); printf(“v3 value is : %c \n”, v3); return 0; } |
How character stores into memory?
- Every character represented by an integer value called ASCII.
- The range of ASCII from 0 to 255(1 byte limits)
- Each character occupies 1 byte memory to store the corresponding integer value.
| #include <stdio.h> int main(){ char v1 = ‘a’; char v2 = ‘5’; char v3 = ‘$’; printf(“v1 value is : %c \n”, v1); printf(“v2 value is : %c \n”, v2); printf(“v3 value is : %c \n”, v3); return 0; } |
Program to display short int information (size and limits):
| #include <stdio.h> int main(){ char v1 = ‘a’; char v2 = ‘5’; char v3 = ‘$’; printf(“%c ascii value is : %d \n”, v1, v1); printf(“%c ascii value is : %d \n”, v2, v2); printf(“%c ascii value is : %d \n”, v3, v3); return 0; } |
Program to display Character type info:
| #include <stdio.h> #include <limits.h> int main() { printf(“Signed short min : %d \n”, SHRT_MIN); printf(“Signed short min : %d \n”, SHRT_MAX); printf(“Unsigned short max : %d \n”, USHRT_MAX); return 0; } |
What happens when we try to store the value beyond the limits of datatype?
- Every variable can store the value within the limits only.
- When limit exceeded, it counts the value in the specified limit and store some other value.
| #include<stdio.h> int main(){ char ch = 130; printf(“ch val : %d \n”, ch); // prints -126 return 0; } |
| #include<stdio.h> int main(){ char c1=256, c2=1024; printf(“c1 : %d \n”, c1); printf(“c2 : %d \n”, c2); return 0; } Output: c1 : 0 c2 : 0 |
| #include<stdio.h> int main() { short s = -32744; printf(“s val : %d \n”, s); return 0; } |
sizeof(): a pre-defined function used to find the size of Variable, value, Datatype etc.
Program to find the sizes of different variables:
| #include <stdio.h> int main(){ char c; short s; float f; printf(“char size : %d \n”, sizeof(c)); // prints-1 printf(“short size : %d \n”, sizeof(s)); // prints-2 printf(“float size : %d \n”, sizeof(f)); // prints-4 return 0; } |
Program to find the sizes of data types directly:
| #include <stdio.h> int main() { printf(“char size : %d \n”, sizeof(char)); printf(“short size : %d \n”, sizeof(short)); return 0; } |
Finding the size of expression: In expression, which type occupies highest memory will be the
| #include <stdio.h> int main(){ char c; short s; printf(“char + short : %d \n”, sizeof(c+s)); return 0; } |
ASCII(American Standards Code of Information Interchange): ASCII represents all the characters of language with constant integer values.
| A-65 B-66 .. .. Z-90 | a-97 b-98 .. .. z-122 | 0-48 1-49 .. .. 9-57 | #-35 $-36 .. .. .. |
scanf():
- C library is a Collection of Header files.
- Header file contains Variables and Functions.
- printf() and scanf() functions belongs to stdio.h header file.
- Printf() function is used to display the information on Monitor(standard output).
- Scanf() function is used to read information from keyboard(standard input)
Address operator:
- We need to specify the location (memory address) using variable to read the data.
- ‘&’ is called Address operator in C.
| #include <stdio.h> int main() { int a; printf(“Enter a value : “); scanf(“%d”, &a); printf(“a value is : %d \n”, a); return 0; } |
Program to display the address of variable:
| #include <stdio.h> int main() { int val=10; char sym=’$’; printf(“Address of val : %d \n”, &val); printf(“Value of val : %d \n”, val); printf(“Address of sym : %d \n”, &sym); printf(“Value of sym : %c \n”, sym); return 0; } |