1230.1——可连续计算的计算器

代码部分及注释

#import "ViewController.h"

//当前操作状态
typedef enum{
    kStatusNum,
    kStatusOperation,
    kStatusDone
}kStatus;

//运算符
typedef enum{
    kOperationTypeAdd = 1,
    kOperationTypeMinus,
    kOperationTypeMultiple,
    kOperationTypeDevide
}kOperationType;

typedef enum{
    kComputeTypePrimary, //+ -
    kComputeTypeSenior
}kComputeType;

@interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *resultLable;
@property (nonatomic,assign) kStatus status;
@property (nonatomic,strong) NSMutableArray *paramMutableArray;
@property (nonatomic,strong) NSMutableArray *operationMutableArray;
@property (nonatomic,strong) NSDictionary *operationEnumDic;
@property (nonatomic,assign) BOOL pointStatus;//判断是否输入的是“.”
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.paramMutableArray = [NSMutableArray array];
    self.operationMutableArray = [NSMutableArray array];
    self.status = kStatusDone;
    self.operationEnumDic = @{@"+":@1, @"-":@2, @"*":@3, @"/":@4};
    self.pointStatus = NO;
}

//数字键
- (IBAction)normalButtonDidClicked:(UIButton *)sender {    
    //获取按钮上的数字
    NSString *num = sender.titleLabel.text;
    NSString *showNum = NULL;
    
    //判断是否为一个数字新的开始
    
    
    if (self.status == kStatusNum) {
        //若不是点，可以拼接显示，如果是一个点则不执行
        
        if (self.pointStatus == NO) {
            NSString *currentNum = self.resultLable.text;
            showNum = [NSString stringWithFormat:@"%@"@"%@",currentNum,num];
        }else{
            //判断是否是一个点
            if (![num isEqualToString:@"."]) {
                NSString *currentNum = self.resultLable.text;
                showNum = [NSString stringWithFormat:@"%@"@"%@",currentNum,num];
            }else{
                showNum = self.resultLable.text;
            }
        }
    }else{
        //判断之前是否有结果，如果有，我们将丢弃这个结果
        if (self.status == kStatusDone) {
            [self.paramMutableArray removeAllObjects];
        }
        
        showNum = num;
        self.status = kStatusNum;
    }
    //判断当前数是否为点
    if([num isEqualToString:@"."]){
        self.pointStatus = YES;
    }
    self.resultLable.text = showNum;
    
    
}

//+/-键
- (IBAction)signChangeButtonDIdClicked:(UIButton *)sender{
    double currentNumTemp = [self.resultLable.text doubleValue]*(-1);
    self.resultLable.text = [NSString stringWithFormat:@"%g",currentNumTemp];
}

//运算符键
- (IBAction)operationButtonDidClicked:(UIButton *)sender {
    //判断是不是重复按下了操作符
    if(self.status != kStatusOperation){
        //改变当前的状态，开始输入新的数字
        self.status = kStatusOperation;
        self.pointStatus = NO;
        //说明当前的数字结束了
        //将这个数字保存在数组中
        [self.paramMutableArray addObject:self.resultLable.text];
        //保存当前按钮上的title
        [self.operationMutableArray addObject:sender.titleLabel.text];
    }else{
        //若已经有操作符，则将现有操作符替换原来的操作符
        //获取当前操作符
        self.pointStatus = NO;
        NSString *newOperation = sender.titleLabel.text;
        //获取最后一个索引值
        NSInteger lastIndex = self.operationMutableArray.count - 1;
        
        [self.operationMutableArray replaceObjectAtIndex:lastIndex withObject:newOperation];
    }
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    
}

//=号键
- (IBAction)equalButtonDidClicked:(UIButton *)sender {
    //添加当前的最后一个数字
    [self.paramMutableArray addObject:self.resultLable.text];
    
    //进行分级运算
    [self computeWithType:kComputeTypeSenior];
    [self computeWithType:kComputeTypePrimary];
    
    //将结果显示到界面上
    self.resultLable.text = [self.paramMutableArray firstObject];
    self.status = kStatusDone;
    self.pointStatus = NO;
    [self.paramMutableArray removeAllObjects];
}

-(void)computeWithType:(kComputeType)type{
    NSString *firstOperation;
    NSString *secondOperation;
    if (type == kComputeTypePrimary) {
        firstOperation = @"+";
        secondOperation = @"-";
    }else{
        firstOperation = @"*";
        secondOperation = @"/";
    }
    
    for (int i = 0; i <self.operationMutableArray.count; i++) {
    //获取i对应的运算符
        NSString *opr = [self.operationMutableArray objectAtIndex:i];
        
        //判断是不是*或者/
        if ([opr isEqualToString:firstOperation]|| [opr isEqualToString:secondOperation]) {
            double firstNum = [[self.paramMutableArray objectAtIndex:i]doubleValue];
            double secondNum = [[self.paramMutableArray objectAtIndex:i+1]doubleValue];
            double result = [self calculate:firstNum second:secondNum operation:opr];
            
            //覆盖相应i对应的值
            [self.paramMutableArray replaceObjectAtIndex:i withObject:[NSString stringWithFormat:@"%g",result]];
            
            //删除后面的一个数和符号
            [self.paramMutableArray removeObjectAtIndex:i+1];
            [self.operationMutableArray removeObjectAtIndex:i];
            
            //i--
            i--;
        }
    }
}

//计算结果
-(double)calculate:(double)firstNum
         second:(double)secondNum
      operation:(NSString*) operation{
    //从字典中获取这个字符串的运算符对应的枚举值
    kOperationType type = [[self.operationEnumDic objectForKey:operation]intValue];
    double result = 0;
    switch (type) {
        case kOperationTypeAdd:
            result = firstNum + secondNum;
            break;
        case kOperationTypeMinus:
            result = firstNum - secondNum;
            break;
        case kOperationTypeMultiple:
            result = firstNum * secondNum;
            break;
        case kOperationTypeDevide:
            result = firstNum / secondNum;
            break;
        default:
            break;
    }
    return result;
}

//重置计算器
- (IBAction)resetButtonDidClicked:(UIButton *)sender {
self.resultLable.text = @"0";
    [self.paramMutableArray removeAllObjects];
    [self.operationMutableArray removeAllObjects];
    self.status = kStatusDone;
    self.pointStatus = NO;
}
@end