Objective-C中的舍入数字

Question

我正在尝试进行一些数字舍入和转换为字符串以增强Objective-C程序中的输出.

我有一个浮点值,我想要舍入到最近的.5然后用它来设置标签上的文本.

例如:

1.4将是一串:1.5

1.2将是一串:1

0.2将是一个字符串:0

我花了一段时间在Google上寻找答案但是,作为Objective-C的菜鸟,我不知道该搜索什么!所以,我真的很感激指向正确的方向!

谢谢,阿什

Answer 1

感谢大家的指点,我设法提出了一个解决方案:

float roundedValue = round(2.0f * number) / 2.0f;
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setMaximumFractionDigits:1];
[formatter setRoundingMode: NSNumberFormatterRoundDown];

NSString *numberString = [formatter stringFromNumber:[NSNumber numberWithFloat:roundedValue]];
[formatter release];

以上是我投入的测试用例,但如果有人知道更好的方法,我会有兴趣听到它!

Answer 2

float floatVal = 1.23456;

四舍五入

int roundedVal = lroundf(floatVal); 

NSLog(@"%d",roundedVal);

围捕

int roundedUpVal = ceil(floatVal); 

NSLog(@"%d",roundedUpVal);

四舍五入

int roundedDownVal = floor(floatVal);

NSLog(@"%d",roundedDownVal);

Answer 3

NSString *numberString = [NSString stringWithFormat:@"%f", round(2.0f * number) / 2.0f];

Answer 4

使用lroundf()将float舍入为整数,然后将整数转换为字符串.

Answer 5

NSString *numberString = [NSString stringWithFormat:@"%d",lroundf(number)];

Answer 6

我建议使用NSNumberFormatter.

Answer 7

一个简单的方法:

float theFloat = 1.23456;
int rounded = roundf(theFloat); NSLog(@"%d",rounded);
int roundedUp = ceil(theFloat); NSLog(@"%d",roundedUp);
int roundedDown = floor(theFloat); NSLog(@"%d",roundedDown);
// Note: int can be replaced by float