添加到NSString

Question

我有一个NSString，我想添加额外的字符。在我看来，我认为它会像这样简单：

NSString *answerString = [NSString stringWithFormat:@"%f", finalVolume] + @" Cubic Feet";

但那没用。有谁知道我在这里可能会缺少什么？谢谢！

Answer 1

NSString是不可变的，所以你不能只是添加它。相反，你要么像这样编写你的字符串：

NSString *answerString = [NSString stringWithFormat:@"%f Cubic Feet", finalVolume];

或

NSString *unit = @"Cubic Feet";
NSString *answerString = [NSString stringWithFormat:@"%f %@", finalVolume, unit];

或创建一个可变的：

NSMutableString *answerString = [NSMutableString stringWithFormat:@"%f ", finalVolume];
[answerString appendString:@"Cubic Feet"];

Answer 2

使用NSMutableString

你可以附加任何你想要的东西......

Answer 3

我很确定你可以做到以下几点：

NSString *answerString = [NSString stringWithFormat:@"%f Cubic Feet", finalVolume];

或者如果要追加的部分需要变量，您可以执行以下操作：

NSString *answerString = [NSString stringWithFormat:@"%f %@", finalVolume, myVariable];

Answer 4

[[NSString stringWithFormat:@"%f", finalVolume] stringByAppendingString:@" Cubic Feet"];

Answer 5

只需使用

NSString *answerString = [NSString stringWithFormat:@"%f %@", finalVolume,@"Cubic Feet"];

Answer 6

NSMutableString *str = [[NSMutableString alloc] init];
[str appendString:@"s1"];
[str appendString:@"s2"];

Answer 7

[NSString stringwithformat:@"%f %@", final value, @"cubic feet"];