oc带顺序连算不带优先级计算器(作为备忘，完成度：95%)

#import "ViewController.h"

@interface
ViewController ()

@property (weak,
nonatomic) IBOutlet
UILabel *res;

@property(nonatomic,assign)double op1;

@property(nonatomic,assign)double op2;

@property(nonatomic,assign)int op;

@property(nonatomic,assign)char sign;

@end

@implementation ViewController
- (IBAction)onClick:(UIButton*)sender {

static
BOOL p=NO;//判断是否第二个操作数

static
BOOL q=NO;//小数操作

static int i=0;

static
double a=0;

static
double b=0;

static
double c=0;

static
double d=0;

double r=0;

switch(sender.tag)
{

case 1:

case 2:

case 3:

case 4:

case 5:

case 6:

case 7:

case 8:

case 9:

case 0:

if(NO==p)
{

if(YES==q)
{
i++;
c=self.op1+(double)sender.tag/pow(10,i);

self.op1=c;

self.res.text=[NSString
stringWithFormat:@"%g",self.op1];
}else{
a=a*10+sender.tag;

self.op1=a;

self.res.text=[NSString
stringWithFormat:@"%g",self.op1];
}
}else{

if(YES==q)
{
i++;
d=self.op2+(double)sender.tag/pow(10,i);

self.op2=d;

self.res.text=[NSString
stringWithFormat:@"%g",self.op2];
}else{
b=b*10+sender.tag;

self.op2=b;

self.res.text=[NSString
stringWithFormat:@"%g",self.op2];
}
}

break;

case 10://+
p=YES;
q=NO;
i=0;

//判断上一次的运算符

if('+'==self.sign)
{
r=self.op1+self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('-'==self.sign)
{
r=self.op1-self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('*'==self.sign)
{
r=self.op1*self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('/'==self.sign)
{
r=self.op1/self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

self.sign='+';

break;

case 11://-
p=YES;
q=NO;
i=0;

if('+'==self.sign)
{
r=self.op1+self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('-'==self.sign)
{
r=self.op1-self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('*'==self.sign)
{
r=self.op1*self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('/'==self.sign)
{
r=self.op1/self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

self.sign='-';

break;

case 12://*
p=YES;
q=NO;
i=0;

if('+'==self.sign)
{
r=self.op1+self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('-'==self.sign)
{
r=self.op1-self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('*'==self.sign)
{
r=self.op1*self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('/'==self.sign)
{
r=self.op1/self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

self.sign='*';

break;

case 13:// /
p=YES;
q=NO;
i=0;

if('+'==self.sign)
{
r=self.op1+self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('-'==self.sign)
{
r=self.op1-self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('*'==self.sign)
{
r=self.op1*self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

if('/'==self.sign)
{
r=self.op1/self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;

self.op2=0;
b=0;
}

self.sign='/';

break;

case 14://=

if('+'==self.sign)
{
r=self.op1+self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;
}

if('-'==self.sign)
{
r=self.op1-self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;
}

if('*'==self.sign)
{
r=self.op1*self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;
}

if('/'==self.sign)
{
r=self.op1/self.op2;

self.res.text=[[NSString
alloc] initWithFormat:@"%g",r];

self.op1=r;
}

self.sign='\0';

self.op2=0;
b=0;

break;

case 15://AC
p=NO;
q=NO;
a=0;
b=0;
c=0;
d=0;
i=0;

self.op1=0;

self.op2=0;

self.sign='\0';

self.res.text=[NSString
stringWithFormat:@"0"];

break;

case 16://.
q=YES;

break;

case 17://%

self.op1=self.op1/100;

self.res.text=[NSString
stringWithFormat:@"%g",self.op1];

break;

case 18://±

self.op1=-1*self.op1;

self.res.text=[NSString
stringWithFormat:@"%g",self.op1];

break;
}
}

- (void)viewDidLoad {

[super
viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning {

[super
didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.
}

@end