如何将负整数转换为char数据类型

Question

I'm trying to solve a postfix expression using a char based stack.
I need to push some negative values into my char based stack such as '-2' but it stores only the '-' part.
My exact code looks like this-

             char val=Character.forDigit(operation(temp),10);
             System.out.println("pushed is "+val);

Output is "pushed is - "
Kindly help.

Answer 1

Character class is singular. As in one character, one digit, so it's only getting the first of '-2'.

See this for a fuller explanation: Difference between "char" and "String" in Java

Answer 2

char means that it consists of 1 character from supported characters in any specific language. -2 isn't 1 character, its a string because it consist of sequence of characters eg, '-' and '1' . So what your code is doing is doing the right thing.

Now, given that you really need characters to store your digits, then you have to map your negative value on to some other characters. Digits from 0..9 are actually ascci # 48..57 . So what you can do is pic 10 consecutive characters from the ascci table and treat them as -ve. Lets say you pick a .. i as your -ve numbers then a = -1, b = -2 and so on ...

Keep in mind that since you are using character, you can't deal with two digit numbers as long as you treat each number as an individual character. Then you have to handle all "decimal" operations.