Having difficulty printing strings

Question

When I run the program, the second printf() prints string2 with whatever was scanned into string1 attached to the end.

e.g.

Answer 1

You need to terminate your array with NULL character as

char string2[5]={'1','2','a','b','\0'};

When you are doing the scanf(), string1 is stored in next memory so it is printing string2 with string1. It will print upto it gets \0 so its Undefined Behavior