None and null? | Sololearn: Learn to code for FREE!

0

None and null?

In sololearner python's >other types> None it says None represent no value 0 or [] , same as NULL in other languages. But when I tried if ((None==0) or (None==[])): print ("true") there was no output for this hence both are unequal now I tried in C if(NULL==0){ printf("true"); } here I got true. so how NULL and None are equal and why None!=0 or None!=[]

5/11/2018 9:56:24 AM

Yugabdh

2 Answers

New Answer

+5

NULL in C is literally defined as `(void*)0` so it makes sense that NULL == 0 because NULL is zero. In Python, None gets it's own type, NoneType, so it is an object made from a class, and makes sense that it isn't == 0. It's more of a language design thing, every language handles their nulls differently. To me this shows that C types are very weak. In C, everything is just a number if you squint hard enough, Python has classes and all that. I think Python is doing the right thing, None is certainly not an array. But C is all about performance and being low-level so it's behaviour makes sense too. Some interesting nulls: PHP's `null` is like you described, `null == []` Javascript has two nulls, `null` and `undefined` Haskell has `undefined`, but as soon as you even look at it, your program crashes SQL's NULL is funny because there NULL != NULL

+1

woah.... Thanks for that one and after NULL!=NULL this definitely None is not similar to other language's NULL xD