[C language] do you really know printf? (printf is typically error prone, and collection is strongly recommended)

What is? printf（）？

What we know printf Is to print out characters , Figures, etc. , But you know printf What is the return type of ？
after cplusplus.com Query for , hear printf The return type of is int type , The returned value is the total number of characters written .

Go straight to the topic ,printf The fallibility of

printf("%d ",printf("%d",printf("%d",43)));

Do you know the result of this statement ？
Think about it ~~~

Actually , The print result of the above statement is ：4 3 2 1

• Why? ？
  because , From the inside out printf("%d ",43) Print is 43, Is that right ？
  then , Because a total of two characters are written （43）, So the one above printf("%d ",43) The return value of is 2;
  Give it to the next printf Print , Print out 2;
  then , Print 2 A total of 1 Characters , therefore printf("%d",2); The return value of is 1;
  Return value 1 By the last one printf（）; Print , End of sentence ;
  Do you understand ？