Java implicit conversion between int and char [duplicate]

Question

I'm looking for an explanation for Java's behavior when handling the following scenarios. I understand that the ASCII table is arranged so that the value of the character 5 is five positions greater than 0. This allows for calculations to be done on the char without converting to an int as seen in the first example.

What I don't understand is why Java seems to inconsistently handle when to provide a value from an ASCII table and when to do a calculation on the chars as though they were integers.

int x = '5' - '0';

output x = 5;

int x = '5'

output x = 53;

Now for some examples, that introduce confusion.

int x = '0' + 1 - '5'

output x = -4

int y = '5' - '0' + '1'

output 54

int y = '5' - 0 + '1'

output 102

Java seems to be doing an implicit type conversion, but how is Java inferring which representation of the int/char should it be using?

Answer 1

Just write the char conversion to ASCII code (below your statements)

int x = '0' + 1 - '5'
        48  + 1 - 53 = -4 

int y = '5' - 0 + '1'
         53 - 0 + 49 = 102

int y = '5' - '0' + '1'
         53 - 48  + 49 = 54

Notice it's consistent, each int remains int and each char converted to ASCII code