What is the difference between 15 and 015? [duplicate]

Question

This might be appear to be a silly/trivial question at first, but when I do this:

char f_gear = 15;

I get the normal output

"☼"

but when I pad it with zeros when i declare it:

char f_gear = 015;

I get weird output makes text look garbled (in one line) and blanks the previous line. When I attempt to see the individual character itself, I get the following:

"  ◘◘@╧S☻ "

What is essentially different? Isn't 15==015?

==EDIT== Stack Overflow changed the text when I posted the question. The output I really saw was a few blank characters.

Answer 1

No, 015 refers to octal number. So, 015 in octal is equal to 13 in decimal.

So,

char f_gear = 015;

is equivalent to

char f_gear = 13;