二進制表達式的無效操作數（'NSMutableArray' 和 'double'）

Question

我想將 double 值存儲到 Array 中，然后結合起來計算一些結果，但我遇到了一些錯誤。 還有另一種方法嗎？

NSMutableArray *storeImpedance;
NSMutableArray *storeLength;

double designFrequency = 1e9;
double simulateFrequency = 1.5e9;
double pi = 3.14159265359;
double omega = 2*pi*simulateFrequency;
double Z0=50;

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    storeImpedance = [[NSMutableArray alloc]initWithCapacity:25];
    storeLength = [[NSMutableArray alloc]initWithCapacity:25];
}

- (IBAction)addButton:(UIButton *)sender {
    storeCount++;
    [storeImpedance addObject:[NSNumber numberWithDouble:[impedanceTextField.text doubleValue]]];
    [storeLength addObject:[NSNumber numberWithDouble:[lengthTextField.text doubleValue]]];

}

if (imageIndex==1)
{
      thetarad=storeImpedance*pi/180*simulateFrequency/designFrequency;
      A=cos(thetarad);
      B=I* storeImpedance*sin(thetarad);
      C=I*sin(thetarad)/storeImpedance;
      D=cos(thetarad);
}

Answer 1

在這一行：

hetarad=storeImpedance*pi/180*simulateFrequency/designFrequency;

您正在使用NSMutableArray類型的storeImpedance並且此表達式中的預期類型是double 。

從數組中提取所需的double值並使用它來解決問題：

NSNumber *number = (NSNumber *)[storeImpedance firstObject]; // Or use objectAtIndex: for a specific value in the array if it is not the first one
double value = [number doubleValue];

hetarad=value*pi/180*simulateFrequency/designFrequency;

如果要為hetarad中的每個值計算hetarad ：

for (id element in storeImpedance) {
    NSNumber *number = (NSNumber *)element 
    double value = [number doubleValue]; 

    hetarad=value*pi/180*simulateFrequency/designFrequency;
    // You should do something with hetarad here (either store it or use in other required logic otherwise it will be overwritten by the next iteration
}