iphone - Xcode Obj-C Why is 7/10 not 0.7

Question

int a=7
int b=10
float answer = (float)a/b;

answer=0.699999988 ( I expect 0.7 ??)

Answer 1

The short version is: Floating points are not accurate, it's only a finite set of bits, and a finite set of bits cannot be used to represent an infinite set of numbers.

The longer version is here: What Every Computer Scientist Should Know About Floating-Point Arithmetic

See also:

How is floating point stored? When does it matter?

Why is my number being rounded incorrectly?