本篇内容介绍了“iOS实现计算器小功能的代码怎么写”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
本文利用ios实现计算器app，后期将用mvc结构重构
import UIKit
class CalculViewController: UIViewController {
@IBOutlet weak var display: UILabel!
var userIsInTheMiddleOFTypingANumber:Bool=false
@IBAction func appendDigit(sender: UIButton) {
let digit=sender.currentTitle!
if userIsInTheMiddleOFTypingANumber {
display.text=display.text!+digit
}else{
display.text=digit
userIsInTheMiddleOFTypingANumber=true
}
}
var operandstack:Array<Double>=Array<Double>()
@IBAction func operate(sender: UIButton) {
let operation=sender.currentTitle!;
if userIsInTheMiddleOFTypingANumber {
enter()
}
switch operation {
case "×":performeOperation{$0*$1}
case "÷":performeOperation{$1/$0}
case "+":performeOperation{$0+$1}
case "-":performeOperation{$1-$0}
case "√":performeOperation{sqrt($0)}
default:
break
}
}
// func multiply(op1:Double,op2:Double) -> Double {
// return op1*op2;
// }
func performeOperation(operation:(Double,Double)->Double){
if operandstack.count>=2 {
displayValue=operation(operandstack.removeLast(),operandstack.removeLast())
enter()
}
}
private func performeOperation(operation:Double->Double){
if operandstack.count>=1 {
displayValue=operation(operandstack.removeLast())
enter()
}
}
@IBAction func enter() {
userIsInTheMiddleOFTypingANumber=false
operandstack.append(displayValue)
print("operandstack=\(operandstack)")
}
var displayValue:Double{
get{
return NSNumberFormatter().numberFromString(display.text!)!.doubleValue
}
set{
display.text="\(newValue)"
userIsInTheMiddleOFTypingANumber=false
}
}计算型属性的setter与getter
swift利用函数作为参数
swift的重载，详情参见：swift override
效果如下
增加model文件
import Foundation
class CalculatorBrain {
private enum Op : CustomStringConvertible{
case operand(Double)
case UnaryOperation(String,Double->Double)
case BinaryOperation(String,(Double,Double)->Double)
var description:String{
get{
switch self {
case .operand(let operand):
return "\(operand)"
case .BinaryOperation(let symbol,_):
return symbol
case .UnaryOperation(let symbol, _):
return symbol
}
}
}
}
private var opstack=[Op]()
private var knowOps=[String:Op]()
init(){
func learnOp(op:Op){
knowOps[op.description]=op
}
learnOp(Op.BinaryOperation("×"){$0*$1})
learnOp(Op.BinaryOperation("÷"){$1/$0})
learnOp(Op.BinaryOperation("+"){$0+$1})
learnOp(Op.BinaryOperation("-"){$1-$0})
learnOp(Op.UnaryOperation("√"){sqrt($0)})
// knowOps["×"]=Op.BinaryOperation("×"){$0*$1}
// knowOps["÷"]=Op.BinaryOperation("÷"){$1/$0}
// knowOps["+"]=Op.BinaryOperation("+"){$0+$1}
// knowOps["-"]=Op.BinaryOperation("-"){$1-$0}
// knowOps["√"]=Op.UnaryOperation("√"){sqrt($0)}
}
private func evaluate(ops:[Op])->(result:Double?,remainOps:[Op]){
if !ops.isEmpty {
var remainOps=ops;
let op=remainOps.removeLast()
switch op {
case Op.operand(let operand):
return(operand,remainOps)
case Op.UnaryOperation(_, let operation):
let operandEvalution=evaluate(remainOps)
if let operand=operandEvalution.result{
return(operation(operand),operandEvalution.remainOps)
}
case Op.BinaryOperation(_, let operation):
let operandEvlution1=evaluate(remainOps)
if let operand1=operandEvlution1.result {
let operandEvlution2=evaluate(operandEvlution1.remainOps)
if let operand2=operandEvlution2.result {
return (operation(operand1,operand2),operandEvlution2.remainOps)
}
}
}
}
return (nil,ops)
}
func evaluate()->Double?{
let (result,remainder)=evaluate(opstack)
print("\(opstack)=\(result)with\(remainder)left over")
return result
}
func pushOperand(operand:Double)->Double?{
opstack.append(Op.operand(operand))
return evaluate()
}
func performOperation(symbol:String)->Double?{
if let operation=knowOps[symbol]{
opstack.append(operation)
}
return evaluate()
}
}controll修改为
import UIKit
class CalculViewController: UIViewController {
@IBOutlet weak var display: UILabel!
var userIsInTheMiddleOFTypingANumber:Bool=false
var brain=CalculatorBrain()
@IBAction func appendDigit(sender: UIButton) {
let digit=sender.currentTitle!
if userIsInTheMiddleOFTypingANumber {
display.text=display.text!+digit
}else{
display.text=digit
userIsInTheMiddleOFTypingANumber=true
}
}
//var operandstack:Array<Double>=Array<Double>()
@IBAction func operate(sender: UIButton) {
if userIsInTheMiddleOFTypingANumber {
enter()
}
if let operation=sender.currentTitle{
if let result=brain.performOperation(operation) {
displayValue=result
}else{
displayValue=0
}
}
}
@IBAction func enter() {
userIsInTheMiddleOFTypingANumber=false
if let result=brain.pushOperand(displayValue){
displayValue=result
}else{
displayValue=0
}
}
var displayValue:Double{
get{
return NSNumberFormatter().numberFromString(display.text!)!.doubleValue
}
set{
display.text="\(newValue)"
userIsInTheMiddleOFTypingANumber=false
}
}
}“iOS实现计算器小功能的代码怎么写”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注亿速云网站，小编将为大家输出更多高质量的实用文章！
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