in c way:

#include <stdio.h>
typedef union {
    float f;
    unsigned u;
} ufloat;

int main(void)
{
    ufloat u1;
    u1.f = 0.01f;
    printf("%x\n", u1.u);
}

in java way:

public class FloatMulti {
    public static void main(String[] args) {
        System.out.println(Integer.toHexString(Float.floatToIntBits(0.01f)));
        System.out.println(Long.toHexString(Double.doubleToLongBits(0.01)));
    }
}

参考资料：
How do I display the binary representation of a float or double?