将参数变量从int转换为char，反之亦然

Question

If I pass a char as a parameter when calling stuff, will it compile? Will passing an int instead of a char work too? I know you can cast from int to char but shouldn't it be explicit?

I have a class Test with one static method of return type String with char a and int x as parameters.

public class Test {
    public static String stuff(char a, int x)
    {
        char b = (char)x; String s = "";
        while (a<b)
        s+=a+b--;
        return s;
    }
    public static void main(String args[])
    {
         System.out.println(stuff('a','d'));
    }
}

Answer 1

是的，传递一个字符是合法的，但是不是一个好习惯。

Answer 2

Up-casting(implicit)-

byte –> short –> int –> long –> float –> double

Down-casting(Explicit)-

double –> float –> long –> int–> short–> byte

int takes 4 bytes of memory and char takes 2 bytes of memory, so requires explicit casting. int can take negative values and char takes only positive values.

      public class Test {
      public static void main(String args[]) { 
      int i = 78;     // 4 bytes 
      // char ch = i;   // error, 4 bytes to 2 bytes
      char ch = (char) i; // int is type converted to char
      System.out.println(ch); // prints N (78 ASCII value for N)

      System.out.println("Max int:"+Integer.SIZE+"bit");
      System.out.println("Max char:"+Character.SIZE+"bit");

       }
     }