问题描述
我有一个简单的计算器应用程序，我希望它是如此，如果答案不需要小数位，没有，只有整数。如果答案是2，我不希望它说2.000000，它应该说2.如果它需要一个小数位，它应该显示一个小数位，例如12.8而不是12.80。我该怎么办？这是我的代码。
顺便说一句，这是来自，而不是我自己的工作。
I have a simple calculator app and I want it to be so that if the answer requires no decimal places, there are none, just whole numbers. If the answer was 2, I don't want it to say 2.000000, it should say 2. If it requires one decimal place, it should show to one decimal place for example 12.8 instead of 12.80. How would I do this? Here is my code.btw, this is from a tutorial at http://www.youtube.com/watch?v=Ihw0cfNOrr4, not my own work.
viewcontroller.h
viewcontroller.h
#import <UIKit/UIKit.h>
interface calcViewController : UIViewController {
float result;
IBOutlet UILabel *calculatorScreen;
int currentOperation;
float currentNumber;
}
-(IBAction)buttonDigitPressed:(id)sender;
-(IBAction)buttonOperationPressed:(id)sender;
-(IBAction)cancelInput;
-(IBAction)cancelOperation;
@end
in。 m
#import "calcViewController.h"
@implementation calcViewController
-(IBAction)buttonDigitPressed:(id)sender {
currentNumber = currentNumber *10 + (float)[sender tag];
calculatorScreen.text = [NSString stringWithFormat:@"%2f", currentNumber];
}
-(IBAction)buttonOperationPressed:(id)sender {
if (currentOperation ==0) result = currentNumber;
else {
switch (currentOperation) {
case 1:
result = result + currentNumber;
break;
case 2:
result = result - currentNumber;
break;
case 3:
result = result * currentNumber;
break;
case 4:
result = result / currentNumber;
break;
case 5:
currentOperation = 0;
break;
}
}
currentNumber = 0;
calculatorScreen.text = [NSString stringWithFormat:@"%2f", result];
if ([sender tag] ==0) result=0;
currentOperation = [sender tag];
}
-(IBAction)cancelInput {
currentNumber =0;
calculatorScreen.text = @"0";
}
-(IBAction)cancelOperation {
currentNumber = 0;
calculatorScreen.text = @"0";
currentOperation = 0;
}
推荐答案
单向是使用NSNumberFormatter来格式化你的结果而不是NSString的 -stringWithFormat：：
One way is to use NSNumberFormatter to format your result instead of NSString's -stringWithFormat::
NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setMaximumFractionDigits:requiredDigits];
[formatter setMinimumFractionDigits:0];
NSString *result = [formatter stringFromNumber:[NSNumber numberWithFloat:currentNumber];
这篇关于如何更改iOS的小数位数？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！