Datatypes in C – What are datatypes in C?

What are datatypes in C? Information sort is a system for outlining varied fundamental properties in regards to the information saved in reminiscence. Properties similar to, sort of information, vary of information, bytes occupied, how these bytes are interpreted, and many others.

For instanceint is an information sort used to outline integer sort variables?
int a; right here a is an integer sort variable. It may well retailer numbers from -2,147,483,648 to +2,147,483,647.

Information sorts in C is assessed in three broad classes.

Datatypes in C - Teche Programmer
Information sorts hierarchy

Primitive information sort

C language helps 4 primitive sorts – charintfloatvoid. Primitive sorts are also referred to as pre-defined or fundamental information sorts.

Information sortMeasurementVaryDescription
char1 byte-128 to +127A personality
int2 or four byte-32,768 to 32,767 or
-2,147,483,648 to +2,147,483,647
An integer
floatfour byte1.2E-38 to three.4E+38Single precision floating level quantity
void1 byte void sort shops nothing

The dimensions and variety of an information sort is machine-dependent and should differ from compiler to compiler. C commonplace requires solely the minimal dimension to be fulfilled by each compiler for every information sort. For instance, the dimension of int sort varies from compiler to compiler, however, it has to be not less than 2 bytes on each compiler.

Character sort char

Any single character worth in C is represented utilizing char. Measurement of sort is 1 byte and may retailer 128 characters.

Instance to outline char sort variable –

char grade = 'A';

In above code grade is outlined as a personality sort variable and may retailer any character.

Learn extra – How to declare character literal (value)?

Integer sort int

In C programming int key phrase is used to outline a quantity sort. Measurement of int is 2 or four bytes (compiler dependent) and may retailer values as much as -32,768 to 32,767 or -2,147,483,648 to +2,147,483,647.

Instance to outline int sort variable –

int roll = 24;

In above code roll is outlined as an integer sort variable and may retailer any quantity in int vary.

Float sort float

An actual sort worth in C is outlined with float or double key phrasefloat defines a single-precision floating-level quantity that may retailer 1.2E-38 to three.4E+38. Whereas double defines a double-precision floating level quantity that may retailer 2.3E-308 to 1.7E+308.

A variety of vital digits after the decimal level is named it’s precision. Precision of float sort is of 6 decimal locations and double is of 15 decimal locations.

Instance to outline float sort variable –

float share = 95.67;
const float PI = 3.14159265359f;
double pace = 2.998e+8;

void sort

As identity suggests void internally doesn’t retailer somethingvoid key phrase is used to outline a perform return sort or a generic pointer.

Instance to outline void pointer sort

void * ptr;

Within the above code ptr is outlined as a void pointer. We are going to find out about void sorts in the later part of this programming tutorial collection.

Derived information sorts

derived information sort is outlined utilizing mixture of qualifiers together with the primitive information sort. Derived sorts are created utilizing fundamental information sorts with modified behavior and property.

Information sort Qualifiers

Qualifiers are optionally available add-on to the fundamental information sorts. They’re used to change the behavior and property of fundamental information sorts yielding new sort with new property and behavior.

There are two forms of information sort qualifiers in C, dimension, and signal qualifier. They’re used together with the fundamental information sorts in any of the 2 given syntax.

[qualifier] <basic-data-type>


<basic-data-type> [qualifier]

Normal syntax to make use of a qualifier

[sign-qualifier] [size-qualifier] <basic-data-type>

Instanceunsigned quick int

Be aware: Elements within the sq. brackets [] are optionally available and elements in the angle bracket < > are obligatory.

Measurement qualifier

Measurement qualifier in C is used to change the dimension of a primitive information sort. C helps two-dimension qualifier, quick and lengthy.

Measurement qualifier is usually used with integer sort. As well asdouble sort helps lengthy qualifier.

Syntax to make use of dimension qualifier

[size-qualifier] <basic-data-type>


<basic-data-type> [size-qualifier]

Instance to make use of dimension qualifier
Information sortDescription
quick intDefines min 2 bytes integer
lengthy intDefines a min four bytes integer
lengthy doubleDefines a min 12 bytes double precision floating level quantity
Guidelines relating to dimension qualifier as per ANSI C commonplace
  • Measurement of quick integer sort quick int is not less than 2 bytes and have to be lower than or equal to the scale of int
  • The dimensions of integer sort int is not less than 2 bytes and have to be better than or equal to the scale of quick.
  • The dimensions of lengthy integer sorts lengthy int is not less than four bytes and have to be better than or equal to the scale of int.
  • The precision of lengthy double have to be better than or equal to double. Precision of double have to be better or equal to the precision of float.

Be aware: quick int might also abbreviated as quick and lengthy int as lengthy. However, there isn’t an abbreviation for lengthy double.

The GCC C compiler helps yet another derived integer sort lengthy lengthy or lengthy lengthy int. Measurement of lengthy lengthy is Eight bytes and may retailer numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

How to find size of a type using sizeof() operator?

Dimension of an information kind is machine-dependent and differs from compiler to compiler. Nevertheless, in programming, there exist conditions when we have to know whole bytes a kind occupies in reminiscence. To search out the actual dimension of a kind in C programming we use sizeof() operator.

sizeof() is a particular operator used to search out the actual dimension of a kind in reminiscence. The sizeof() operator returns an integer i.e. whole bytes wanted in reminiscence to characterize the sort of worth or expression.

The sizeof() is a way used operator by programmers. It is rather helpful for growing moveable applications.

Learn extra – Operators in C programming

Syntax to make use of sizeof() operator

sizeof() operator can be utilized in numerous means.


Instance to make use of sizeof() operator

#embrace &lt;stdio.h>

int primary()

Output of the above program.

Dimension of char = 1
Dimension of int = 4
Dimension of expression (3+2.5) = 8

Questioning, how sizeof(3 + 2.5) is 8? C performs integer promotion to verify all operands in an expression are of comparable kind. All operands of expression is promoted to increased kind i.e. double kind (since 2.5 is of double kind). Therefore the expression sizeof(3 + 2.5) is equal to sizeof(double).

Be awareThe above program is compiled on the GCC C compiler. The outcomes could differ from compiler to compiler.

Program to search out dimension of knowledge varieties

 * C program to search out dimension of fundamental and derived varieties utilizing sizeof() operator

#embrace &lt;stdio.h>

int primary()

	printf("sizeof(char) = %d\n\n", sizeof(char));
	printf("sizeof(brief) = %d\n", sizeof(brief));
	printf("sizeof(int) = %d\n", sizeof(int));
	printf("sizeof(lengthy) = %d\n", sizeof(lengthy));
	printf("sizeof(lengthy lengthy) = %d\n\n", sizeof(lengthy lengthy));
	printf("sizeof(float) = %d\n", sizeof(float));
	printf("sizeof(double) = %d\n", sizeof(double));
	printf("sizeof(lengthy double) = %d\n", sizeof(lengthy double));
	return 0;


sizeof(char) = 1

sizeof(brief) = 2
sizeof(int) = 4
sizeof(lengthy) = 4
sizeof(lengthy lengthy) = 8

sizeof(float) = 4
sizeof(double) = 8
sizeof(lengthy double) = 12

The above program we used sizeof(kind) to search out its dimension. Nevertheless, it’s usually advisable to make use of variable identify i.e. sizeof(variable-name) as an alternative of a kind identity. As if a kind has modified in this system the entire program wants to not be modified.

How to find the range of a data type in C?

In C programming knowledge sorts play a significant position, so is their dimension and vary. The sizeof() operator offers you bytes required to retailer worth of some sort in reminiscence. Nevertheless, in programming, it’s essential to pay attention to vary of a kind to keep away from overflow and underflow errors.

The dimensions of an information sort are compiler dependent and so is its vary. So, it’s essential to not hardcode dimensions and vary values in your program.

There are two methods to seek out minimal and most vary of a kind. You should use any of the methods to get vary of a kind.

Discover vary of knowledge sorts manually with out C library

The minimal and most vary of a signed sort is given by –
-(2N-1) to 2N-1 - 1 (The place N is sizeof(sort) * 8 i.e. a complete variety of bits utilized by the kind)

The minimal and most vary of an unsigned sort is given by –
0 to (2N-1) + (2N-1 - 1)

Allow us to test this programmatically.

 * C program to seek out vary of knowledge sort

#embrace &lt;stdio.h>

void printUnsignedRange(int bytes)

    int bits = 8 * bytes;
    unsigned lengthy lengthy to = (1LLU &lt;&lt; (bits - 1)) + ((1LL &lt;&lt; (bits - 1)) - 1);;
    printf(" Zero to %llu\n\n", to);

void printSignedRange(int bytes)

int principal()

    printf("Vary of char =");
    printf("Vary of unsigned char =");
    printUnsignedRange(sizeof(unsigned char));
    printf("Vary of brief =");
    printf("Vary of unsigned brief =");
    printUnsignedRange(sizeof(unsigned brief));
    printf("Vary of int =");
    printf("Vary of unsigned int =");
    printUnsignedRange(sizeof(unsigned int));
    printf("Vary of lengthy =");
    printf("Vary of unsigned lengthy =");
    printUnsignedRange(sizeof(unsigned lengthy));
    printf("Vary of lengthy lengthy =");
    printSignedRange(sizeof(lengthy lengthy));
    printf("Vary of unsigned lengthy lengthy =");
    printUnsignedRange(sizeof(unsigned lengthy lengthy));
    return 0;

Within the above program, I’ve used a bitwise left shift << operator to calculate the energy of two.

Learn extra about – Bitwise left shift << operator in C programming


Vary of char = -128 to 127

Vary of unsigned char = Zero to 255

Vary of brief = -32768 to 32767

Vary of unsigned brief = Zero to 65535

Vary of int = -2147483648 to 2147483647

Vary of unsigned int = Zero to 4294967295

Vary of lengthy = -2147483648 to 2147483647

Vary of unsigned lengthy = Zero to 4294967295

Vary of lengthy lengthy = -9223372036854775808 to 9223372036854775807

Vary of unsigned lengthy lengthy = Zero to 18446744073709551615

Discover vary of knowledge sorts utilizing C library

The above method to get vary of any sort is cool, nevertheless not beneficial to make use of. It’s all the time beneficial to make use of the facility of pre-defined C library.

In C programming minimal and most constants are outlined beneath two header records data – limits.h and float.h.

limits.h defines constants associated with integer and character sorts. Equivalent to minimal and most dimensions vary, complete bits, and so on.

float.h defines constants associated with floating level numbers. Equivalent to precision, minimal and most dimension, and so on.

Allow us to use the C library to get minimal and most vary of an information sort.

 * C program to get minimal and most vary of a kind utilizing C library constants
#embrace &lt;stdio.h>
#embrace &lt;limits.h>
#embrace &lt;float.h>

int principal()


Vary of signed char -128 to 127
Vary of unsigned char Zero to 255

Vary of signed brief int -32768 to 32767
Vary of unsigned brief int Zero to 65535

Vary of signed int -2147483648 to 2147483647
Vary of unsigned int Zero to 4294967295

Vary of signed lengthy int -2147483648 to 2147483647
Vary of unsigned lengthy int Zero to 4294967295

Vary of signed lengthy lengthy int -9223372036854775808 to 9223372036854775807
Vary of unsigned lengthy lengthy int Zero to 18446744073709551615

Range of float 1.175494e-038 to 3.402823e+038
Range of double 2.225074e-308 to 1.797693e+308 
Range of long double -0.000000e+000 to -1.#QNAN0e+000

Signal qualifier

The signal qualifier in C is used to specify the signed nature of integer sorts. It specifies whether or not a variable can maintain damaging worth or not.

Signal qualifiers are used with integer int and character char sort.

C helps two signal qualifier, signed and unsignedsigned specifies a variable can maintain each constructive in addition to damaging integers. unsigned specifies a variable will solely maintain constructive integers.

Instance to make use of signal qualifier

signed quick int
unsigned lengthy
unsigned char

By default, integer and character sorts are signed in nature. Therefore, utilizing signed key phrase is ineffective. Nevertheless, the programmer will use to explicitly specify the signed nature of the variable.

Person outlined information sort

Regardless of a number of fundamental and derived sort, C language helps function to outline our customized sort primarily based on our want. Person outlined sort embody array, pointer, buildings, unions, enumeration sorts, and many others.

At this level with little information on C programming, it’s unimaginable to clarify consumer-outlined sorts. I’ll cowl all of them in upcoming sections of this tutorial collection.

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