Question

我的印象是，使用像％0.1f这样的格式说明符会在标准4/5分割后对浮点值进行舍入（即3.24将舍入为3.2，而3.25将舍入为3.3）。然而，我没有得到我期望的结果。这是我的测试代码：

NSLog(@"%0.1f", 3.24); //Output: 3.2
NSLog(@"%0.1f", 3.25); //Output: 3.2  Expected Output: 3.3
NSLog(@"%0.1f", 3.26); //Output: 3.3

即使使用NSNumberFormatter也会产生相同的结果：

    NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
    [formatter setNumberStyle:NSNumberFormatterDecimalStyle];
    [formatter setRoundingMode: NSNumberFormatterRoundHalfUp]; //Tried with and without setting this.  Same results either way.
    [formatter setMaximumFractionDigits:1];

    NSString *numberString1 = [formatter stringFromNumber:[NSNumber numberWithFloat:3.24]];
    NSString *numberString2 = [formatter stringFromNumber:[NSNumber numberWithFloat:3.25]];
    NSString *numberString3 = [formatter stringFromNumber:[NSNumber numberWithFloat:3.26]];

    NSLog(@"Result...%@",numberString1); //Output: 3.2
    NSLog(@"Result...%@",numberString2); //Output: 3.2  Expected: 3.3
    NSLog(@"Result...%@",numberString3); //Output: 3.3

似乎是基本的东西。我做错了什么？

使用NSString和％f时的舍入问题

0 个答案: