What will be the output of following 4 lines of codes? const char* p =…

Explanation:

const char* p = "Hello";

printf ("%c ", *p);// note space in format string

printf ("%c ", *++p); // value of ++p is p after the increment

printf ("%c ", *p++); // value of p++ is p before the increment

printf ("%c ", *p);// value of p has been incremented as a side effect of p++

Program declares p as a pointer to char. When we say "pointer to a char", what does that mean? It means that the value of p is the address of a char; p tells us where in memory there is some space set aside to hold a char.

The statement also initializes p to point to the first character in the string literal "Hello". For the sake of this exercise, it's important to understand p as pointing not to the entire string, but only to the first character, 'H'. After all, p is a pointer to one char, not to the entire string. The value of p is the address of the 'H' in "Hello".

const char* p = "Hello";

printf ("%c ", *p);// prints value pointed by pointer p i.e. H

printf ("%c ", ++p); // preincrement and has same precedence and ++ and * are right to left associative, hence value of ++p is p after the increment

printf ("%c ", p++); // postincrement has higher precedence than . But, the value of p++ is the value of p before the increment. So *p++, will be value before increment i.e. 'e'.

// After execution of above statement the value will be incremented now and p will be pointing to index location of l.

printf ("%c ", *p);// The current pointer value pointed by p is l.