CODEWITHSUNDEEP
iosobjective-c
Stefan
Stefan

Reputation: 1335

Adding values from button to UILabel

I am learning Xcode(objective C). I want to make simple calculator.

I started by adding four simple buttons and one label. Two buttons are for numbers(1 and 2), and I added variables into .m file:

int *one = 1;
int *two = 2;

Next step what I've done is that I made action on button clicked and said that label take value from that button:

self.firstLabel.text=[NSString stringWithFormat:@"%d", one);

And I made same action for another button.

Everything is fine until this step, what I want to do next is when I click on number button to add value to that label, then when I click to divide(/) button to add / sign and when I click to another button to add another value.

I want to be something like this in label: 2 / 1, and when i click = button to divide them and show result. Thanks.

EDIT:

I also added label proper into .h, and when I click on button it shows me only one value in label.

Upvotes: 1

Views: 562

Answers (3)

rmp
rmp

Reputation: 3503

Since you are just starting to learn obj C you may want to keep your calculator simple, building a fully functional calc. can get surprisingly complex. You should consider using an RPN approach, it will make things much easier, you can just push the numbers to a stack and perform operations one at a time. Something like: 2, enter, 1, enter + enter.

You may also want to have a look at Stanford's iOS course on Apple University, the course is in Swift but the class project was a calculator so it should give you a good reference point. Hope that helps and good luck!

Upvotes: 1

Nameet
Nameet

Reputation: 650

You are only setting the int value to the label. You need to append the value maintaining the previous text so that it appears as "2 / 1". I'll suggest using tags for the buttons and use a common method for number buttons in your calculator. This is more sort of logical thing rather than specific to iOS and Xcode. Similarly when "=" is pressed use a method to calculate the result.

Upvotes: 0

ennioma
ennioma

Reputation: 353

you should add a custom target for each button, i.e.,

- (IBAction)addDivide:(id)sender {
    self.firstLabel.text = [[NSString alloc] initWithFormat:@"%@ /", self.firstLabel.text];
}

Any action will update your label.

Just a further advice for you, don't name the label as "firstLabel", try to give it a name tied to its semantics.

Upvotes: 0

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