Type Casting In Groovy

Question

I have two questions.

I did the following code to find the ASCII value of $ :

def a = "\$"
def b = (int)a 
println b //prints 36

Well I'm happy with the answer. But when I tried to do it in reverse like this, I found I'm missing something :

def a = 36
String b = a
println b // getting output only 36 

Question 1:

So my first question is why it prints 36 and why not $? Am I wrong here?

Well if the same first code block is re-written as:

    def a = "\$"
    def b = a as int
    println b

If I run this program I get an error like this :

Caught: java.lang.NumberFormatException: For input string: "$"
    at T.run(T.groovy:2)

Even though I'm trying to do the same as before. I'm getting an error.

Question 2:

So why does the as keyword doesn't work here and does def a = (int)b is not equal to to def a = b as int? Explain me.

Thanks in advance.

Answer 1

when you cast a string to int it's ok while you have one char in it, so we can say you cast a char to int, when you try to cast int to a string i think it uses toString method or something like that. Try to cast 36 to char and you'll see your '$'