Yes The functions of finding absolute value in C language are abs( x) and fbs( x), and abs( x) is contained in stdlib.h, both of which are contained in the math header file.

1, abs( x) function

Format: intabs (int I);

Function: Find the absolute value of an integer.

Example:

# include & ltstdio.h & gt

# include & ltstdlib.h & gt

# include & ltmath.h & gt

Master ()

{

int a = 1，b =-2；

Printf ("the absolute value of %d is% d and the absolute value of% d is %d\n", a, abs( a), b, ABS (b));

}

The running result is: the absolute value of 1 is 1, and the absolute value of -2 is 2.

2.fabs( x) function

Format: float fabs (float I); /double fab (double x);

Function: Find the absolute value of floating-point number.

Example:

# include & ltstdio.h & gt

# include & ltmath.h & gt

Master ()

{

float a = 1.4，b =-2.7；

Printf ("the absolute value of f is %f, and the absolute value of f is %f\n", a, fabs( a), b, fabs (b));

}

The running results are: the absolute value of 1.400000 is 1.400000, and the absolute value of -2.700000 is 2.700000.

Extended data:

Other math.h header files contain function descriptions:

1, trigonometric function

Double)； crime; sine

Double cos (double); cosine

Shuangtan (double); tangent

2. Inverse trigonometric function

double asin(double)； The result is between [-PI/2, PI/2]

Double acos (double); The result is between [0, PI]

Double (double); Arctangent (principal value), the result is between [-PI/2, PI/2]

double atan2 (double，double)； Arctangent (integer value), the result is between [-PI, PI]

3. Hyperbolic trigonometric functions

Double sinh (double);

Double cosh (double);

Double tanh (double);

4. Exponents and Logarithms

double frexp(double value，int * exp)； This is a method to split a value into a fractional part f and an exponential part exp (base 2), and return the fractional part f, that is, f * 2 exp. Where the value of f is in the range of 0.5~ 1.0 or 0.

double ldexp(double x，int exp)； This function is just the opposite of the frexp function above, and the return value is x * 2 exp.

double modf(double value，double * iptr)； Split a value and return its fractional part, with iptr pointing to the integer part.

Double; Logarithm based on e

double log 10(double)； Logarithm based on 10

Double power (double x, double y); Calculate the y power of x

Floating point powf (floating point x, floating point y); This function is the same as pow, except that the input and output are single-precision floating-point numbers.

Double exp (double); Find the power of natural number e

double sqrt(double)； square root

5, rounding

Double ceiling (double); Rounds up and returns the smallest integer not less than x.

Double floor (double); Take the integer down and return the largest integer not greater than x, which is the Gaussian function [x]