meterwhite / mathstringexpression Goto Github PK

777777*9999999结果是7777769222223.000576

- (NSString *)createResultString:(NSString *)calcuStr{ NSDecimalNumber *decimalResult = [MSParser parserComputeNumberExpression:calcuStr error:nil]; NSInteger decimalNum = 9; NSDecimal decimal = decimalResult.decimalValue; NSDecimal desDecimal; NSDecimalRound(&desDecimal, &decimal ,decimalNum, NSRoundPlain); NSDecimalNumber *result = [NSDecimalNumber decimalNumberWithDecimal:desDecimal]; NSString *res = [result stringValue]; return res; }

例如排列组合C(3,1)或者A（3，3）怎么写？

"SUM(2,6,3, SUM(100,SUM(3,4)) + MAX(6,7)”

0.3-0.2=0.09999999999999998

计算结果为：-0
转JS表达式结果为：((-1)×0)

/**
* 例4 使用JavaScript定义函数
/
NSError errorJSFun;
MSFunctionOperator* opFunJS = [MSFunctionOperator operatorWithJSFunction:@"function And(a, b){return a + b;}" error:&errorJSFun];
[tab setElement:opFunJS];
NSString* jsExpString = @"And(1,1)";//

BOOL allRight = [MSExpressionHelper helperCheckExpression:jsExpString usingBlock:^(NSError *error, NSRange range) {
    
    NSLog(@"%@",error);
}];

if(allRight){
    
    //计算表达式
    NSString* computeResult = [MSParser parserComputeExpression:jsExpString error:nil];
    NSLog(@"计算结果为：%@",computeResult);
    
    //表达式转JS表达式
    NSString* jsExpression = [MSParser parserJSExpressionFromExpression:jsExpString error:nil];
    NSLog(@"转JS表达式结果为：%@",jsExpression);
}

最后输出的计算结果为NAN，表达式为(1,1)

算9++这种不完整的表达式时直接就崩溃了