c++ - Does "pointerVariable ==" mean something different from "pointerVariable="? -


for example: 

node * curr; if(curr = null)

vs 

node * curr; if(curr == null)

what each of these things mean?

yes, different.

the first example uses assignment operator (=) , assigns null tocurr, , value used condition if. since it's null, , null considered false when comes conditions, execution never enter block. bug , @ least gcc , clang emit warning it.

the second 1 uses comparison operator (==) compare curr null. if curr equal null, execution enter block. curr remains unchanged.


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