In c #, 0 is used to represent a very small Numbers, int integer 0, float will not, such as float a=0, 10/a result is up, so I wrote a piece of code to find it, now that float can save the decimal values, illustrate the decimal in the range of float, but I use double inside the smallest value in addition to it, or up, use a for loop, push the decimal point in the future a bit at a time when the decimal point is beyond the scope of float, became 0, this contradiction from the previous deduction, so what the hell am I how to know how much is the decimal?