带e是指10的 e后面次方
#include <iostream> int main() { float f; f = 9.87654321f; std::cout << f << std::endl; f = 987.654321f; std::cout << f << std::endl; f = 987654.321f; std::cout << f << std::endl; f = 9876543.21f; std::cout << f << std::endl; f = 0.0000987654321f; std::cout << f << std::endl; return 0; }
输出：
9.87654 987.654 987654 9.87654e+006 9.87654e-005
