iOS 四舍五入、进位、抹位 方法

1，四舍五入法

float numberToRound;

    int result;

    numberToRound = 5.61;

    result = (int)roundf(numberToRound);

    NSLog(@"roundf(%.2f) = %d", numberToRound, result);

    //输出 roundf(5.61) = 6

 

numberToRound = 5.41;

result = (int)roundf(numberToRound);

NSLog(@"roundf(%.2f) = %d", numberToRound, result);

//输出 roundf(5.41) = 5

 

 

2、进位方法

float numberToRound;

    int result;

    numberToRound = 5.61;

    result = (int)ceilf(numberToRound);

    NSLog(@"ceilf(%.2f) = %d", numberToRound, result);

    //输出 ceilf(5.61) = 6

 

numberToRound = 5.41;

result = (int)ceilf(numberToRound);

NSLog(@"ceilf(%.2f) = %d", numberToRound, result);

//输出 ceilf(5.41) = 6

 

 

3、抹位方法

float numberToRound;

    int result;

    numberToRound = 5.61;

    result = (int)floorf(numberToRound);

    NSLog(@"floorf(%.2f) = %d", numberToRound, result);

    //输出 floorf(5.61) = 5

 

numberToRound = 5.41;

result = (int)floorf(numberToRound);

NSLog(@"floorf(%.2f) = %d", numberToRound, result);

//输出 floorf(5.41) = 5

 

 ⚠️注意的坑

NSLog(@"%d", (int) ceil(10 / 3)); 输出结果却是：3

NSLog(@"%d",  (int)ceil(10 / 3.0));  输出结果就是：4