Constants refer to the fixed values that can not be changed throughout the entire program.

Constants can be of any data type and is divided into Integer Numerals, Floating-Point Numerals, Characters, Strings and Boolean Values.

Integer literals

An integer literal can have suffix like U or L, for unsigned and long, respectively. The suffix can be uppercase or lowercase and can be in any order.

212         // Legal
215u        // Legal
0xFeeL      // Legal
078         // Illegal: 8 is not an octal digit
032UU       // Illegal: cannot repeat a suffix

Following are other examples of various types of Integer literals:

85         // decimal
0213       // octal
0x4b       // hexadecimal
30         // int
30u        // unsigned int
30l        // long
30ul       // unsigned long

Floating-point literals

A floating-point literal can have integer,decimal,fractional ,exponent part. You can represent floating point literals either in decimal form or exponential form.

3.14159       // Legal
314159E-5L    // Legal
510E          // Illegal: incomplete exponent
210f          // Illegal: no decimal or exponent
.e55          // Illegal: missing integer or fraction

Character Literals

Character literals are enclosed in the single quotes. If the literal begins with L (uppercase only), it is called as a wide character literal .