iOS 四舍五入、进位、摸位 方法

iOS开发中经常遇到 浮点数的 四舍五入、进位、摸位 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、摸位方法

 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