type conversion - type - Cómo convertir un flotador a un Int redondeando al entero entero más cercano

tipos de conversión

Question

¿Hay alguna forma de convertir un float en un Int redondeando al entero entero posible más cercano?

Answer 1

Para redondear al uso más cercano roundf (), para redondear use ceilf (), para redondear use floorf (). Espero que este ejemplo demuestre ...

#import "math.h"

...

float numberToRound;
int result;

numberToRound = 4.51;

result = (int)roundf(numberToRound);
NSLog(@"roundf(%f) = %d", numberToRound, result); // roundf(4.510000) = 5

result = (int)ceilf(numberToRound);
NSLog(@"ceilf(%f) = %d", numberToRound, result); // ceilf(4.510000) = 5

result = (int)floorf(numberToRound);
NSLog(@"floorf(%f) = %d", numberToRound, result); // floorf(4.510000) = 4


numberToRound = 10.49;

result = (int)roundf(numberToRound);
NSLog(@"roundf(%f) = %d", numberToRound, result); // roundf(10.490000) = 10

result = (int)ceilf(numberToRound);
NSLog(@"ceilf(%f) = %d", numberToRound, result); // ceilf(10.490000) = 11

result = (int)floorf(numberToRound);
NSLog(@"floorf(%f) = %d", numberToRound, result); // floorf(10.490000) = 10


numberToRound = -2.49;

result = (int)roundf(numberToRound);
NSLog(@"roundf(%f) = %d", numberToRound, result); // roundf(-2.490000) = -2

result = (int)ceilf(numberToRound);
NSLog(@"ceilf(%f) = %d", numberToRound, result); // ceilf(-2.490000) = -2

result = (int)floorf(numberToRound);
NSLog(@"floorf(%f) = %d", numberToRound, result); // floorf(-2.490000) = -3

numberToRound = -3.51;

result = (int)roundf(numberToRound);
NSLog(@"roundf(%f) = %d", numberToRound, result); // roundf(-3.510000) = -4

result = (int)ceilf(numberToRound);
NSLog(@"ceilf(%f) = %d", numberToRound, result); // ceilf(-3.510000) = -3

result = (int)floorf(numberToRound);
NSLog(@"floorf(%f) = %d", numberToRound, result); // floorf(-3.510000) = -4

La documentación...

https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/roundf.3.html

https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/ceil.3.html

https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/floor.3.html

Answer 2

En realidad, la respuesta de Paul Beckingham no es del todo correcta. Si prueba un número negativo como -1.51, obtiene -1 en lugar de -2.

Las funciones round (), roundf (), lround () y lroundf () de math.h también funcionan para números negativos.

Answer 3

Qué tal esto:

float f = 1.51; int i = (int) (f + 0.5);

Answer 4

(int)floor(f+0.5);

Prueba esto...