Types of Literals in C/C++ with Examples

Last Updated : 30 Sep, 2019

The values assigned to each constant variables are referred to as the literals. Generally, both terms, constants and literals are used interchangeably. For eg, “const int = 5;“, is a constant expression and the value 5 is referred to as constant integer literal. There are four types of literals in C and five types of literals in C++.

The literals of C/C++ are divided accordingly:

Integer Literals: These are used to represent and store the integer values. Integer literals are expressed in two types i.e.,

Prefixes: The Prefix of the integer literal indicates the base in which it is to be read.
For example:
```
0x10 = 16

Because 0x prefix represents a HexaDecimal base.
So 10 in HexaDecimal is 16 in Decimal.
Hence the value 16. 
```
There are basically represent in four types.
1. Decimal-literal(base 10): A non-zero decimal digit followed by zero or more decimal digits(0, 1, 2, 3, 4, 5, 6, 7, 8, 9).
  For example:
```
56, 78
```
2. Octal-literal(base 8): a 0 followed by zero or more octal digits(0, 1, 2, 3, 4, 5, 6, 7).
  For example:
```
045, 076, 06210
```
3. Hex-literal(base 16): 0x or 0X followed by one or more hexadecimal digits(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, A, b, B, c, C, d, D, e, E, f, F).
  For example:
```
0x23A, 0Xb4C, 0xFEA
```
4. Binary-literal(base 2): 0b or 0B followed by one or more binary digits(0, 1).
  For example:
```
0b101, 0B111
```
Suffixes: The Prefix of the integer literal indicates the type in which it is to be read.
For example:
```
12345678901234LL 
indicates a long long integer value 12345678901234
because of the suffix LL
```
These are represented in many ways according to their data types.
1. int: No suffix is required because integer constant is by default assigned as an int data type.
2. unsigned int: character u or U at the end of an integer constant.
3. long int: character l or L at the end of an integer constant.
4. unsigned long int: character ul or UL at the end of an integer constant.
5. long long int: character ll or LL at the end of an integer constant.
6. unsigned long long int: character ull or ULL at the end of integer constant.

Example:

C

#include <stdio.h>
  
int main()
{
  
    // constant integer literal
    const int intVal = 10;
  
    printf("Integer Literal:%d \n",
           intVal);
    return 0;
}

C++

#include <iostream>
using namespace std;
  
int main()
{
    // constant integer literal
    const int intVal = 10;
    cout << "Integer Literal: "
         << intVal << "\n";
  
    return 0;
}

Output:

Integer Literal:10

Floating-Point Literals: These are used to represent and store real numbers. The real number has an integer part, real part, fractional part and an exponential part. The floating-point literals can be stored either in decimal form or exponential form. While representing the floating-point decimals one must keep two things in mind to produce valid literals:

In the decimal form, one must include the decimal point, exponent part or both, otherwise, it will lead to an error.
In the exponential form, one must include the integer part, fractional part or both, otherwise, it will lead to an error.

Few floating-point literal representations are shown below:

Valid Floating Literals:

10.125
1.215-10L
10.5E-3

Invalid Floating Literals:

123E
1250f
0.e879

Example:

C

#include <stdio.h>
  
int main()
{
    // constant float literal
    const float floatVal = 4.14;
  
    printf("Floating point literal: %.2f\n",
           floatVal);
    return 0;
}

C++

#include <iostream>
using namespace std;
  
int main()
{
    // Real literal
    const float floatVal = 4.14;
  
    cout << "Floating-point literal: "
         << floatVal << "\n";
    return 0;
}

Output:

Floating point literal: 4.14

Character Literal: This refers to the literals that are used to store a single character within a single quote. To store multiple characters, one needs to use a character array. Storing more than one character within a single quote will throw a warning and displays just the last character of the literal. It gives rise to the following two representations:

char type: This used to store normal character literal or the narrow-character literals. This is supported by both C and C++.
Example:
```
// For C
char chr = 'G';

// For C++
char chr = 'G';
```
wchar_t type: This literal is suppoirted only in C++ and not in C. If the character is followed by L, then the literal needs to be stored in wchar_t. This represents wide-character literal.
Example:
```
// Not Supported For C

// For C++
wchar_t chr = L'G';
```

Example:

C

#include <stdio.h>
  
int main()
{
    // constant char literal
    const char charVal = 'A';
  
    printf("Character Literal: %c\n",
           charVal);
    return 0;
}

C++

#include <iostream>
using namespace std;
  
int main()
{
    // constant char literal
    const char charVal = 'A';
  
    // wide char literal
    const wchar_t charVal1 = L'A';
  
    cout << "Character Literal: "
         << charVal << "\n";
    cout << "Wide_Character Literal: "
         << charVal1 << "\n";
  
    return 0;
}

Output:

Character Literal: A

Escape Sequences: There are various special characters that one can use to perform various operations.

String Literals: String literals are similar to that of the character literals, except that it can store multiple characters and uses a double quote to store the same. It can also accommodate the special characters and escape sequences mentioned in the table above.
Example:
```
// For C
char stringVal[] = "GeeksforGeeks";

// For C++
string stringVal = "GeeksforGeeks"
```
Example:
C
#include <stdio.h>

int main()
{
    const char str[]
        = "Welcome\nTo\nGeeks\tFor\tGeeks";
    printf("%s", str);
    return 0;
}
C++
#include <iostream>
using namespace std;

int main()
{
    const string str
        = "Welcome\nTo\nGeeks\tFor\tGeeks";
    cout << str;
    return 0;
}
Output:
```
Welcome
To
Geeks    For    Geeks
```

Boolean Literals: This literal is provided only in C++ and not in C. They are used to represent the boolean datatypes. These can carry two values:

true: To represent True value. This must not be considered equal to int 1.
false: To represent False value. This must not be considered equal to int 0.

Example:

// C++ program to show Boolean literals
  
#include <iostream>
using namespace std;
  
int main()
{
    const bool isTrue = true;
    const bool isFalse = false;
  
    cout << "isTrue? "
         << isTrue << "\n";
    cout << "isFalse? "
         << isFalse << "\n";
  
    return 0;
}

Output:

isTrue? 1
isFalse? 0

Related articles on Constants/Literals in C/C++:

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