Question

How could I add a and b without using the + symbol, because I am assigning the + symbol in the c variable?

I know how to form an expression using the above data as shown in the code below, but I don’t know how to get the output of that expression using NSExpression.

This is my code:

int a=10;
int b=20;
NSString *c=@"+";

NSString *d=[NSString stringWithFormat:@"%d%@%d",a,c,b];

nslog(@"d=%@",d);//d=10+20

After this, how do I get the answer 30?

Answer 1

int a = 10;
int b = 20;
NSString *c = @"+";

NSString *s = [NSString stringWithFormat:@"%d %@ %d", a, c, b];
NSExpression *e = [NSExpression expressionWithFormat:s];
int result = [[e expressionValueWithObject:nil context:nil] intValue];

NSLog(@"%d", result);