Thread: Interesting Question

Salem's answer involves integer ranges, and I think that's too complex. Besides, it doesn't answer the question.

I was never so much for the coding part, but rather the fact that he mentions that you can't be sure that the computer adds correctly, and therefore, in essence, the programmer has to convince himself that the output is expected.

Even with an operation as trivial as addition, the computer is no replacement for the human brain. Only the programmer can know what is right and what is wrong.

Originally Posted by Happy_Reaper

you can't be sure that the computer adds correctly, and therefore, in essence, the programmer has to convince himself that the output is expected.

But that's misleading. I think the original question was really whether the computer could make basic mistakes like adding 1 and 1 and getting 3. It was a 5-year-old asking the question.

The programmer can do only so much. He can check that no overflow will occur, but for the actual calculation he has to trust the CPU. What will he do? assert() that a+b == a+b?

To be honest I'd frankly tell him to try it and see if the computer gets it wrong. And if that doesn't convince him, to tell him to keep trying until he either finds the computer making a mistake, or is convinced it won't make a mistake.