ios - 在简单的计算器应用程序中删除不必要的零

Question

我做了一个简单的计算器，每次我点击计算它都会给出一个答案，但给出了六个不必要的零，我的问题是，我该如何删除这些零？

NSString *firstString = textfieldone.text;
NSString *secondString = textfieldtwo.text;

NSString *LEGAL = @"0123456789";
NSCharacterSet *characterSet = [[NSCharacterSet characterSetWithCharactersInString:LEGAL] invertedSet];
NSString *filteredOne = [[firstString componentsSeparatedByCharactersInSet:characterSet] 
                         componentsJoinedByString:@""];
NSString *filteredTwo = [[secondString componentsSeparatedByCharactersInSet:characterSet] 
                         componentsJoinedByString:@""];
firstString = filteredOne;
secondString = filteredTwo;

//Here we are creating three doubles
double num1;
double num2;
double output;
//Here we are assigning the values 
num1 = [firstString doubleValue];
num2 = [secondString doubleValue];

output = num1 + num2;

label.text = [NSString stringWithFormat:@"%f",output];

例子:

15 + 15 = 30.000000

Answer 1

我想补充一点，如果您使用 %g 说明符，那么这些都不是必需的。