C语言 int float 转 float方法

#include "stdio.h"

int main(void)
{
	float fa = -123.56;
	unsigned char farray[4] = { 0 };

	*(float*)farray = fa;
	printf("farray[0]=%#X,farray[1]=%#X,farray[2]=%#X,farray[3]=%#Xn", farray[0], farray[1], farray[2], farray[3]);
	printf("%fn", *(float*)farray);

	return (0);
}

结果：

farray[0]=0xB8,farray[1]=0x1E,farray[2]=0xF7,farray[3]=0xC2
-123.559998

#include "stdio.h"

union {
	float fa;
	unsigned char farray[4];
}utemp;

int main(void)
{
	int i = 0;
	float ft = 0.0;

	utemp.fa = (float)123.56;
	printf("farray[0]=%#X,farray[1]=%#X,farray[2]=%#X,farray[3]=%#Xn", utemp.farray[0], utemp.farray[1], utemp.farray[2], utemp.farray[3]);
	ft = *(float*)utemp.farray;

	printf("%fn", ft);

	return (0);
}

结果：

farray[0]=0xB8,farray[1]=0x1E,farray[2]=0xF7,farray[3]=0x42
123.559998

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• 2

#include "stdio.h"
#include "string.h"

int main(void)
{
	float fa;
	unsigned char farray[4];
	float ft;

	fa = 45.23;
	memcpy(farray, &fa, sizeof(farray));
	printf("farray[0]=%#X,farray[1]=%#X,farray[2]=%#X,farray[3]=%#Xn", farray[0], farray[1], farray[2], farray[3]);
	memcpy(&ft, &farray, sizeof(farray));
	printf("%fn", ft);

	return (0);
}

结果：

farray[0]=0x85,farray[1]=0xEB,farray[2]=0x34,farray[3]=0x42
45.230000

建议使用共同体进行转换，提高系统的稳定性。