c語言中取絕對值的函數

轉自：http://blog.csdn.net/chaoi/archive/2007/09/18/1790515.aspx

/* ABS.C: This program computes and displays * the absolute values of several numbers. */ #include <stdio.h> #include <math.h> #include <stdlib.h> void main( void ) { int ix = -4, iy; long lx = -41567L, ly; double dx = -3.141593, dy; iy = abs( ix ); printf( "The absolute value of %d is %d/n", ix, iy); ly = labs( lx ); printf( "The absolute value of %ld is %ld/n", lx, ly); dy = fabs( dx ); printf( "The absolute value of %f is %f/n", dx, dy ); } Output The absolute value of -4 is 4 The absolute value of -41567 is 41567 The absolute value of -3.141593 is 3.141593