Bring the best of human thought and AI automation together at your work. Explore Stack Internal ... Save this question. Show activity on this post. ... Closed 5 years ago. I know that char is a primitive type while Character is a class, but I'm confused on when to use which? More on stackoverflow.com

Almost nobody seems to answer your question, what is the point of it, how is that type useful? The answer is simple, because you can do some nice things with chars. You can turn an uppercase into a lowercase letter and the other way around, by changing a single bit: public char toLower(char c) { return c | 0x20; } public char toUpper(char c) { return c & ~0x20 } public char toggleLowerUpper(char c) { return c ^ 0x20 } These (and other) bitwise operations make no sense on strings, but they do on chars. Also, there are methods specifically directed at string. How are you gonna write a method that removes whitespaces, if you can't even detect whether a character is a whitespace? For most things, a string of length 1 is as good as a char, if you ignore the tiny performance penalty, but sometimes you have to work on chars. More on reddit.com

As I understand it, when you cast an int to a char, it doesn't directly translate. It gives you the character equivalent to that int's ASCII code. So when you cast the number 1 to char, the resulting char will be the character that is equivalent to the ASCII code 1. In this case, that is the Start of Heading character which is a control character and is not printable. The ASCII code for the number 1 is 49, so if you were to set a = 49, your output would be the char '1'. Or if you wanted to still use 1 in your variable you would have to do something like a = 1 + '0' because the ASCII code for '0' is 48. More on reddit.com

Since 'a' is a character (not a string), it can be converted into an int (its ascii value, 97). So in effect, that part is effectively saying ca[c - 97]. From what little context is provided, it seems c is a variable holding a lowercase character, so subtracting 'a' from it is a way to convert it to an array index (like 'a'-'a'=0, 'b'-'a'=1, etc.) allowing you to then increment the value held in that index when you find the appropriate character. The subtraction is so that you don't need 96 pointless indexes in the array, before the first lowercase character in ascii. More on reddit.com