Don't confuse this with static vs. dynamic typing!
You all know JavaScripts/PHPs infamous type systems:
PHP example:
echo "123abc"+2; // 125 - the reason for this is explained
// in the PHP docs but still: This hurts
echo "4"+1; // 5 - Oh please
echo "ABC"*5; // 0 - WTF
// That's too much, seriously now.
// This here might be actually a use for weak
typing, but no -
// it has to output garbage.
JavaScript example:
// A good old JavaScript, maybe you'll do better?
alert("4"+1); // 51 - Oh come on.
alert("abc"*3); // NaN - What the...
// Have your creators ever heard of the word "consistence"?
Python example:
# Python's type system is actually a mix
# It spits errors on senseless things like the first example below AND
# allows intelligent actions like the second example.
>>> print("abc"+1)
Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
print("abc"+1)
TypeError: Can't convert 'int' object to str implicitly
>>> print("abc"*5)
abcabcabcabcabc
Ruby example:
puts 4+"1" // Type error - as supposed
puts "abc"*4 // abcabcabcabc - makes sense
After these examples it should be clear that PHP/JavaScript probably have the most inconsistent type systems out there. This is a fact and really not subjective.
Now when having a closer look at the type systems of Ruby and Python it seems like they are having a much more intelligent and consistent type system.
I think these examples weren't really necessary as we all know that PHP/JavaScript have a weak and Python/Ruby have a strong type system. I just wanted to mention why I'm asking this.
Now I have two questions:
When looking at those examples, what are the advantages of PHPs and JavaScripts type systems? I can only find downsides:
They are inconsistent and I think we know that this is not good
Types conversions are hardly controllable
Bugs are more likely to happen and much harder to spot
Do you prefer one of the both systems? Why?
Personally I have worked with PHP, JavaScript and Python so far and must say that Pythons type system has really only advantages over PHPs and JavaScripts.
Does anybody here not think so? Why then?
