can I convert + as an NSString to addition operator directly?

Question

I have a mathematical equation in string format.

Is there a way to convert @"+"(String constant) directly to addition operator in objective C Or

I have to use If-Else statements to solve this equation ??

Answer 1

NSPredicate * parsed = [NSPredicate predicateWithFormat:@"123+456+678-985 = 0"];
NSExpression * left = [(NSComparisonPredicate *)parsed leftExpression];
NSNumber * result = [left expressionValueWithObject:nil context:nil];
float i = [result floatValue];

Answer 2

if([yourString isEqualToString:@"+"])
{
     //Do something

}

This code should work.

Answer 3

You can use NSExpression to achieve this

NSString *expressionFormat = [NSString stringWithFormat:@"(%d %@ %d)",firstNumber,arcthimaticOperator,secondNumber];
NSExpression *expression = [NSExpression expressionWithFormat:expressionFormat];
NSNumber *result = [expression expressionValueWithObject:nil context:nil];
NSLog(@"%@", result);

Please make sure you enter the correct format else the above code will throw exception.