无法实现计算，打印到label上

Question

应用中点击计算按钮时的代码：

 float sqft = ([textfield1.text floatValue]);
float thick= ([textfield2.text floatValue]);
float cos = ([textfield3.text floatValue]);
float eff = ([textfield4.text floatValue]);

float num = ((thick*.5)*sqft)/eff;
float cost = (num*cos);
float costft = (cost/sqft);

label1.text = [NSString stringWithFormat:@"%2.f",num];
label2.text = [NSString stringWithFormat:@"%2.f",cost];
label3.text = [NSString stringWithFormat:@"%2.f",costft];

但是label只返回0？我设置了标签为字符串。但是结果是一样的。

Answer 1

问题是%2.f。

%2.f返回的答案是2 数字的格式，如果结果小于或等于0.5。那么答案就会得0

float sqft = ([textfield1.text floatValue]);
float thick= ([textfield2.text floatValue]);
float cos = ([textfield3.text floatValue]);
float eff = ([textfield4.text floatValue]);

float num = ((thick*.5)*sqft)/eff;
float cost = (num*cos);
float costft = (cost/sqft);

label1.text = [NSString stringWithFormat:@"%2f",num];
label2.text = [NSString stringWithFormat:@"%2f",cost];
label3.text = [NSString stringWithFormat:@"%2f",costft];