[hoytech]

Consider this javascript function:

    function add(a,b) { return a + b; }

Although no conversion is requested explicitly in the function definition, a conversion may take place depending on the types of the arguments passed in:

    > add(1,2)
    3
    >add("1",2)
    "12"

The article in question defines implicit conversion in this way, and in my experience it's a fairly common term.

I was pointing out that per this definition, the article is wrong in saying that perl's + operator may perform an implicit conversion. In perl the + operator always performs a numeric conversion of both its operands, regardless of types. By writing + you are explicitly requesting numeric conversion of both arguments.

In general perl doesn't perform implicit conversion (of course there are some exceptions -- it is perl after all). It does this by not overloading operators like + for different operations such as addition and concatenation.

This also has the nice property that you can count on a+b == b+a, unlike python for instance. (However, in python PEP-465, non-commutativity was a stated advantage of adopting @ for matrix multiplication instead of overloading *, go figure).