C Language Floating Point Constants

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The C language has three mandatory real floating point types, float, double, and long double.

float f = 0.314f;        /* suffix f or F denotes type float */
double d = 0.314;        /* no suffix denotes double */
long double ld = 0.314l; /* suffix l or L denotes long double */

/* the different parts of a floating point definition are optional */
double x = 1.; /* valid, fractional part is optional */
double y = .1; /* valid, whole-number part is optional */

/* they can also defined in scientific notation */
double sd = 1.2e3; /* decimal fraction 1.2 is scaled by 10^3, that is 1200.0 */

The header <float.h> defines various limits for floating point operations.

Floating point arithmetic is implementation defined. However, most modern platforms (arm, x86, x86_64, MIPS) use IEEE 754 floating point operations.

C also has three optional complex floating point types that are derived from the above.

Integer types and constants