E,g
class Test {
public:
void setVal(const std::string& str) {
this.isVal = str; //This will error out
}
private:
string isVal;
};
views:
485answers:
4
+29
A:
In C++, this is a pointer (as opposed to a reference). So you have to say this->isVal instead.
Chris Jester-Young
2009-01-22 02:21:12
+15
A:
Adding to Chris's answer, you can also do:
(*this).isVal = str;
However, it's better to do what Chris said, as it is more orthodox. This is just illustrating that you need to de-reference the pointer before calling methods on it.
FryGuy
2009-01-22 02:23:56
Why was this down-voted? It's perfectly legal... (Ignoring possible operator overloads.)
strager
2009-01-22 02:27:10
I'm voting this back up. It's not the way I'd do it but it is legal, and therefore helpful. What happens if your keyboard ">" key is broken and you're on a tight deadline? :-).
paxdiablo
2009-01-22 02:29:34
...use trigraphs? :-P :-P :-P
Chris Jester-Young
2009-01-22 02:32:09
(Clearly a facetious comment, because there is no trigraph or digraph that makes the <> characters---but there are ones that _use_ those characters! :-P)
Chris Jester-Young
2009-01-22 02:33:44
Wow, I didn't think it'd be that controversial. I was just trying to use the non-syntactic-sugar version to illustrate that "this" is a pointer.
FryGuy
2009-01-22 02:34:29
what about <:0:> hehe.
Johannes Schaub - litb
2009-01-22 02:35:08
anyway, this guys answer works irrespective of any operator overloads. so it's rly 100% equivalent always.
Johannes Schaub - litb
2009-01-22 02:36:38
You could even do: Test that.isVal = str;
Ates Goral
2009-01-22 02:37:33
Well I think this kind of answer with out explanation especially for someone who is obviously a beginner isn't that great of an answer. That could just be me though.
Adam Peck
2009-01-22 02:37:47
Whoa. Is this actually legal? Is it part of the C++ spec that (*this).isVal is functionally different from (Test b=*this; b.isVal)? Because it seems like they should both return a *new* instance similar to the original, but the former actually affects `this`.
Chuck
2009-01-22 02:41:56
@Chuck: Read Ates's comment more carefully. They said: "Test that.isVal = str;" meaning that "that" is a _reference_ to (not a new copy of) this.
Chris Jester-Young
2009-01-22 02:43:50
Johannes Schaub - litb
2009-01-22 02:44:38
I found it helpful, although the answer should probably say "But you wouldn't do this."
too much php
2009-01-22 02:46:38
+8
A:
You also don't really need to use this explicitly to access member variables/methods. You can simply say:
isVal = str;
sth
2009-01-22 02:35:48
personally, I favor explicitly using this, as it allows you to shadow parameter names (which prevents stupid dummy names) and it works with templates and dependent bases.
coppro
2009-01-22 06:13:33