I would like to ask, how to assign a uint32 variable to a uint8 variable?

深圳小花

I would like to ask, how to assign a uint32 variable to a uint8 variable? [Copy link]

 

邀请：@maychang   @damiaa   @skywalker_lee   @Gen_X   参与回复

The following code

unsigned char c1 ;
unsigned int i1 ;

i1=0x12 34 5678;

i1=i1>>16;

i1=i1 & 0x000000ff;

c1=i1;

I want to assign the values of 3 and 4 in the i1 variable to the variable c1.

Excuse me, is there any error in the final c1=i1?

深圳小花

Teacher maychang , I clearly replied, why can't I see it, moderator?

javnson

I think your function is implemented numerically.

As for the last question "Is there an error in the final c1=i1?" If it is a program judgment here, then (c1 == i1) = true, and its judgment mechanism is to force the conversion of uint8_t into uint32_t.

深圳小花

javnson posted on 2022-5-15 21:51 I think your function has been realized numerically. As for the last question "Is there an error in the last c1=i1?" If it is a program...

grateful.

深圳小花

javnson posted on 2022-5-15 21:51 I think your function has been realized numerically. As for the last question "Is there an error in the last c1=i1?" If it is a program...

I want to ask, if I assign 32-bit data directly to an 8-bit variable, will there be any anomalies?

javnson

Shenzhen Xiaohua published on 2022-5-16 08:53 I want to ask, if 32-bit data is directly assigned to an 8-bit variable, there will be no abnormality, right?

Won't

mingplus

i1 = i1 >> 16; c1 = (unsigned char)(i1 & 0xff); // C type conversion, I am used to using (TYPE); In addition c1 = (unsigned char)(i1 & 0xff) = (unsigned char)i1 = i1

深圳小花

mingplus posted on 2022-5-16 11:00 i1 = i1 >> 16; c1 = (unsigned char)(i1 & 0xff); // C mandatory class...

Thank you very much. Is it OK to have c1=i1 without enforcing type conversion? I just want to get the lowest byte of i1?

Gen_X

Correct operation!

no problem!

lkh747566933

I am a newbie, I am here to learn. From my limited knowledge, it seems that there is no mistake

freebsder

Truncate and find out.

fjdeepblue

i1 = i1 >> 16; The result is that i1 is 0, and you cannot get the result you want.