开卷友谊！！！！
今天发表我的第一篇博客对如下字符串公式的计算
该博文在博主http://blog.sina.com.cn/u/1958357554的基础上添加了三角函数
例如字符串str=@"2*sin(90/3)+5+cos(5*10+10)+10+tan(15*3)"
result=17.50
进入主题：.h
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
@interface ViewController : UIViewController
+ (NSString *)calcComplexFormulaString:(NSString *)formula;
@end
.m
#import "ViewController.h"
#import <math.h>
@interface ViewController ()
{
UITextField *_textField;
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
_textField=[[UITextField alloc]initWithFrame:CGRectMake(30, 50, 300, 50)];
_textField.backgroundColor=[UIColor yellowColor];
_textField.text=@"2*sin(30)+5+cos(30)+tan(30)";
[self.view addSubview:_textField];
UIButton *button=[[UIButton alloc]initWithFrame:CGRectMake(20, 100, 50, 50)];
button.backgroundColor=[UIColor redColor];
[button addTarget:self action:@selector(click) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];
}
-(void)click
{
NSString *result = [ViewController calcComplexFormulaString:_textField.text];
NSLog(@"result=%@",result);
}
// 字符串加
+ (NSString *)addV1:(NSString *)v1 v2:(NSString *)v2 {
CGFloat result = [v1 floatValue] + [v2 floatValue];
return [NSString stringWithFormat:@"%.2f", result];
}
// 字符串减
+ (NSString *)subV1:(NSString *)v1 v2:(NSString *)v2 {
CGFloat result = [v1 floatValue] - [v2 floatValue];
return [NSString stringWithFormat:@"%.2f", result];
}
// 字符串乘
+ (NSString *)mulV1:(NSString *)v1 v2:(NSString *)v2 {
CGFloat result = [v1 floatValue] * [v2 floatValue];
return [NSString stringWithFormat:@"%.2f", result];
}
// 字符串除
+ (NSString *)divV1:(NSString *)v1 v2:(NSString *)v2 {
CGFloat result = [v1 floatValue] / [v2 floatValue];
return [NSString stringWithFormat:@"%.2f", result];
}
// 字符串sin
+ (NSString *)sinV1:(NSString *)v1 {
NSLog(@"v1 %0.4f",v1.floatValue);
double result =sin([v1 floatValue]*M_PI/180.0);
return [NSString stringWithFormat:@"%.4f", result];
}
// 字符串cos
+ (NSString *)cosV1:(NSString *)v1 {
NSLog(@"v1 %0.4f",v1.floatValue);
double result =cos([v1 floatValue]*M_PI/180.0);
return [NSString stringWithFormat:@"%.4f", result];
}
// 字符串tan
+ (NSString *)tanV1:(NSString *)v1 {
NSLog(@"v1 %0.4f",v1.floatValue);
double result =tan([v1 floatValue]*M_PI/180.0);
return [NSString stringWithFormat:@"%.4f", result];
}
// 简单只包含 + - 的计算
+ (NSString *)calcSimpleFormula:(NSString *)formula {
NSString *result = @"0";
char symbol = '+';
int len = (int)formula.length;
int numStartPoint = 0;
for (int i = 0; i < len; i++) {
char c = [formula characterAtIndex:i];
if (c == '+' || c == '-') {
NSString *num = [formula substringWithRange:NSMakeRange(numStartPoint, i - numStartPoint)];
switch (symbol) {
case '+':
result = [self addV1:result v2:num];
break;
case '-':
result = [self subV1:result v2:num];
break;
default:
break;
}
symbol = c;
numStartPoint = i + 1;
}
}
if (numStartPoint < len) {
NSString *num = [formula substringWithRange:NSMakeRange(numStartPoint, len - numStartPoint)];
switch (symbol) {
case '+':
result = [self addV1:result v2:num];
break;
case '-':
result = [self subV1:result v2:num];
break;
default:
break;
}
}
return result;
}
// 获取字符串中的前置数字
+ (NSString *)firstNumberWithString:(NSString *)str {
int numEndPoint = (int)str.length;
for (int i = 0; i < str.length; i++) {
char c = [str characterAtIndex:i];
if ((c < '0' || c > '9') && c != '.') {
numEndPoint = i;
break;
}
}
return [str substringToIndex:numEndPoint];
}
// 获取字符串中的后置数字
+ (NSString *)lastNumberWithString:(NSString *)str {
int numStartPoint = 0;
for (int i =(int)str.length-1; i >= 0; i--) {
char c = [str characterAtIndex:i];
if ((c < '0' || c > '9') && c != '.') {
numStartPoint = i + 1;
break;
}
}
return [str substringFromIndex:numStartPoint];
}
// 包含 * / 的计算
+ (NSString *)calcNormalFormula:(NSString *)formula {
NSRange mulRange = [formula rangeOfString:@"*" options:NSLiteralSearch];
NSRange divRange = [formula rangeOfString:@"/" options:NSLiteralSearch];
// 只包含加减的运算
if (mulRange.length == 0 && divRange.length == 0) {
return [self calcSimpleFormula:formula];
}
// 进行乘除运算
int index = (int)mulRange.length > 0 ? (int) mulRange.location : (int)divRange.location;
// 计算左边表达式
NSString *left = [formula substringWithRange:NSMakeRange(0, index)];
NSString *num1 = [self lastNumberWithString:left];
left = [left substringWithRange:NSMakeRange(0, left.length - num1.length)];
// 计算右边表达式
NSString *right = [formula substringFromIndex:index + 1];
NSString *num2 = [self firstNumberWithString:right];
right = [right substringFromIndex:num2.length];
// 计算一次乘除结果
NSString *tempResult = @"0";
if (index == mulRange.location) {
tempResult = [self mulV1:num1 v2:num2];
} else if(index == divRange.location) {
tempResult = [self divV1:num1 v2:num2];
}
// 代入计算得到新的公式
NSString *newFormula = [NSString stringWithFormat:@"%@%@%@", left, tempResult, right];
return [self calcNormalFormula:newFormula];
}
// 三角函数计算公式计算,接口主方法
+ (NSString *)calcSanJiaoFormulaString:(NSString *)formula
{
NSRange sinRange = [formula rangeOfString:@"sin" options:NSLiteralSearch];
NSRange cosRange = [formula rangeOfString:@"cos" options:NSLiteralSearch];
NSRange tanRange = [formula rangeOfString:@"tan" options:NSLiteralSearch];
if (sinRange.length==0&&cosRange.length==0&&tanRange.length==0) {
return [self calcNormalFormula:formula];
}
else if (sinRange.length==3) {
// 获取sin左边的表达式
NSString *left1 = [formula substringWithRange:NSMakeRange(0, sinRange.location)];
// 获取sin括号右边的表达式
NSString *right1 = [formula substringFromIndex:sinRange.location+3];
NSString *right2 =[formula substringFromIndex:sinRange.location+8];
NSString *tempResult;
tempResult = [self sinV1:right1];
formula = [NSString stringWithFormat:@"%@%@%@", left1, [self calcNormalFormula:tempResult],right2];
}
else if (cosRange.length==3) {
// 获取sin左边的表达式
NSString *left1 = [formula substringWithRange:NSMakeRange(0, cosRange.location)];
// 获取sin括号右边的表达式
NSString *right1 = [formula substringFromIndex:cosRange.location+3];
NSString *right2 =[formula substringFromIndex:cosRange.location+8];
NSString *tempResult;
tempResult = [self cosV1:right1];
formula = [NSString stringWithFormat:@"%@%@%@", left1, [self calcNormalFormula:tempResult],right2];
}
else if (tanRange.length==3) {
// 获取sin左边的表达式
NSString *left1 = [formula substringWithRange:NSMakeRange(0, tanRange.location)];
// 获取sin括号右边的表达式
NSString *right1 = [formula substringFromIndex:tanRange.location+3];
NSString *right2 =[formula substringFromIndex:tanRange.location+8];
NSString *tempResult;
tempResult = [self tanV1:right1];
formula = [NSString stringWithFormat:@"%@%@%@", left1, [self calcNormalFormula:tempResult],right2];
}
return [self calcSanJiaoFormulaString:formula];
}
// 复杂计算公式计算,接口主方法
+ (NSString *)calcComplexFormulaString:(NSString *)formula {
// 左括号
NSRange lRange = [formula rangeOfString:@"(" options:NSBackwardsSearch];
if (lRange.length == 0) {
return [self calcSanJiaoFormulaString:formula];
}
// 右括号
NSRange rRange = [formula rangeOfString:@")" options:NSLiteralSearch range:NSMakeRange(lRange.location, formula.length-lRange.location)];
// 获取括号左右边的表达式
NSString *left = [formula substringWithRange:NSMakeRange(0, lRange.location)];
NSString *right = [formula substringFromIndex:rRange.location + 1];
// 括号内的表达式
NSString *middle = [formula substringWithRange:NSMakeRange(lRange.location+1, rRange.location-lRange.location-1)];
// 代入计算新的公式
NSString *newFormula = [NSString stringWithFormat:@"%@%@%@", left, [self calcNormalFormula:middle], right];
return [self calcComplexFormulaString:newFormula];
}
结束战斗！复制即可用！再次感谢http://blog.sina.com.cn/u/1958357554博主的启发引导，如果有用随便拿走
