what is the purpose of putting a space in scanf like this scanf(“ %c”,&ch) in place of scanf(“%c”,&ch)? [duplicate]

Answer 1

scanf(" %c",&ch);

As per the man page,

White space (such as blanks, tabs, or newlines) in the format string match any amount of white space, including none, in the input.

Stdin is standard input.The user enters the data for the program, this is first stored in a buffer and then when the program requests data transfers by use of the read operation the data is made available to the program. (using scanf etc).