I'm having trouble with some fairly basic math functions in Xcode

Basically, the program has 5 textfields for numbers. I wan开发者_如何学JAVAt a math function that totals all 5 textboxes, then multiplies by 1.39, then again by 1.12, but I can't get the textfields to add properly. It works so far if you only put a number in one of the textfields, but it gets a little confused when it comes to adding more than one textfield. Here's my code:

- (IBAction)calculate {
    float b = ([BCB.text floatValue]);
    float d = b+([MCD.text floatValue]);
    float f = b+d+([SF.text floatValue]);
    float w = b+d+f+([SW.text floatValue]);
    float a = b+d+f+w+([AP.text floatValue]);
    float p = 1.39f;
    float h = 1.12f;
    float t = a*p*h;    

    Total.text = [ [NSString alloc] initWithFormat:@"%.2f", t];
}

Bear in mind I'm 100% beginner when it comes to Xcode, and I've kind of Frankensteined this code together from various tutorials, and this might be completely wrong.

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In the line:

float f = b+d+([SF.text floatValue]);

d already equals b+([MCD.text floatValue]), so f is assigned the value of 2*b + ([MCD.text floatValue]), and more error builds up in the next two lines. Just assign each floatValue to a variable by itself (i.e., float f = [SF.text floatValue]; and so on) and then add them all together at the end.

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You should add the value of each text field only once, e.g.:

- (IBAction)calculate {
    float b = [BCB.text floatValue];
    float d = [MCD.text floatValue];
    float f = [SF.text floatValue];
    float w = [SW.text floatValue];
    float a = [AP.text floatValue];
    float p = 1.39f;
    float h = 1.12f;
    float t = (b+d+f+w+a)*p*h;    

    Total.text = [ [NSString alloc] initWithFormat:@"%.2f", t];
}