看看这个问题，用简单的办法解决

[我看你有戏]

words := []byte{0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x20,0x21,0x22,0x23,0x24,0x25}

将上面的的数组的第2，3两个字节 "0x13,0x14 "修改成该数组的长度，小端编码方式

代码最好通用性,words长度可能会变，越简单越好，谢谢

[svenwang]

func WriteUint16(b []byte, n uint16) {
	b[0] = byte(n & 0xff)
	b[1] = byte(n >> 8)
}

func main() {
	words := []byte{0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x20,0x21,0x22,0x23,0x24,0x25}
	WriteUint16(words[2:4], uint16(len(words)))
}