At this article you can learn how to create your own iOS calculator app, Motion Calculator. I share the source code on my Github account.

Firs step create file ViewController.swift on your project:

//  بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ
//
//  ViewController.swift
//  Motion Calculator
//
//  Created by Afriwan Ahda on 12/31/17.
//  Copyright © 2017 Motion Studio. All rights reserved.
//

import UIKit

enum Operation:String {
    case Add = "+"
    case Subtract = "-"
    case Divide = "/"
    case Multiply = "*"
    case NULL = "Null"
}

class ViewController: UIViewController {
    
    @IBOutlet weak var outputLbl: UILabel!
    
    var runningNumber = ""
    var leftValue = ""
    var rightValue = ""
    var result = ""
    var currentOperation:Operation = .NULL
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        outputLbl.text = "0"
    }
    
    @IBAction func numberPressed(_ sender: RoundButton) {
        if runningNumber.count <= 9 {
            runningNumber += "\(sender.tag)"
            outputLbl.text = runningNumber
        }
        
    }
    
    @IBAction func dotPressed(_ sender: RoundButton) {
        if runningNumber.count <= 8 {
            runningNumber += "."
            outputLbl.text = runningNumber
        }
        
    }
    
    @IBAction func equalsPressed(_ sender: RoundButton) {
        operation(operation: currentOperation)
    }
    
    @IBAction func addPressed(_ sender: RoundButton) {
        operation(operation: .Add)
    }
    
    @IBAction func substractPressed(_ sender: RoundButton) {
        operation(operation: .Subtract)
    }
    
    @IBAction func multiplyPressed(_ sender: RoundButton) {
        operation(operation: .Multiply)
    }
    
    @IBAction func dividePressed(_ sender: RoundButton) {
        operation(operation: .Divide)
    }
    
    @IBAction func allClearPerssed(_ sender: RoundButton) {
        runningNumber = ""
        leftValue = ""
        rightValue = ""
        result = ""
        currentOperation = .NULL
        outputLbl.text = "0 "
        
    }
    
    func operation(operation: Operation) {
        if currentOperation != .NULL {
            if runningNumber != "" {
                rightValue = runningNumber
                runningNumber = ""
                
                if currentOperation == .Add {
                    result = "\(Double(leftValue)! + Double(rightValue)!)"
                } else if currentOperation == .Subtract {
                    result = "\(Double(leftValue)! - Double(rightValue)!)"
                } else if currentOperation == .Multiply {
                    result = "\(Double(leftValue)! * Double(rightValue)!)"
                } else if currentOperation == .Divide {
                    result = "\(Double(leftValue)! / Double(rightValue)!)"
                }
                
                leftValue = result
                if (Double(result)!.truncatingRemainder(dividingBy: 1) == 0) {
                    result = "\(Int(Double(result)!))"
                }
                outputLbl.text = result
            }
            currentOperation = operation
        } else {
            leftValue = runningNumber
            runningNumber = ""
            currentOperation = operation
        }
        
    }
    
    
}

Second step, create file RoundButton.swift for circle view of the button:

//  بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ
//
//  RoundButton.swift
//  Motion Calculator
//
//  Created by Afriwan Ahda on 12/31/17.
//  Copyright © 2017 Motion Studio. All rights reserved.
//

import UIKit

@IBDesignable

class RoundButton: UIButton {

    @IBInspectable var roundButton:Bool = false {
        didSet {
            if roundButton {
                layer.cornerRadius = frame.height / 2
            }
        }
    }
    
    override func prepareForInterfaceBuilder() {
        if roundButton {
            layer.cornerRadius = frame.height / 2
        }
    }

}

for the storyboard and others file download full source code, you can modify and learn much how to make iOS app from the source code. Happy code!

Posted on: November 20, 2018, by : Afriwan Ahda