float有效位數

#include <iostream>

using namespace std;

int main()

{

float a = 2.31111111111;

cout<<(float)a<<endl;

float b = 22.221111111111;

cout<<b<<endl;

float c = 0.22111111111;

cout<<c<<endl;

return 1;

}

2.31111

22.2211

0.221111