Unexpected results when printing array and char to screen with cout

Question

As a beginner of learning C++, I am trying to understand the difference between an array of type char and an array of type int. Here is my code:

Answer 1

1.

Because char arrays are treated differently to other arrays when you stream them to cout - the << operator is overloaded for const char*. This is for compatibility with C, so that null-terminated char arrays are treated as strings.

See this question.

2.

This is due to integral promotion. When you call the binary + with a char (with value 'a') and an int (with value 1), the compiler promotes your char to either a signed int or an unsigned int. Which one is implementation specific - it depends on whether char is signed or unsigned by default, and which int can take the full range of char. So, the + operator is called with the values '97' and '1', and it returns the value '98'. To print that as a char, you need to first cast it:

cout << "Print char array[0]+1: " << static_cast(array[0]+1) << endl;

See this question.