Step 1: const char *s = ""; The constant variable s is declared as an pointer to an array of characters type and initialized with an empty string. Step 2: char str[] = "Hello"; The variable str is declared as an array of charactrers type and initialized with a string "Hello". Step 3: s = str; The value of the variable str is assigned to the variable s. Therefore str contains the text "Hello". Step 4: while(*s){ printf("%c", *s++); } Here the while loop got executed untill the value of the variable s is available and it prints the each character of the variable s. Hence the output of the program is "Hello".