what is difference between . and ->

[abdul]

I saw some code here and somebody decaled a type like:

POINT pt;

Now here accessed the "x" value in the variable pt like this:

switch(pt -> x)

Can I write the samething as:

switch(pt.x)

Is there any difference when you use "->" and "." ?

[parksie]

There's a big difference. See the other threads about -> because I don't want to type it out again

[denniswrenn]

Originally posted by abdul
I saw some code here and somebody decaled a type like:

POINT pt;

Now here accessed the "x" value in the variable pt like this:

switch(pt -> x)

Can I write the samething as:

switch(pt.x)

Is there any difference when you use "->" and "." ?

when you have a pointer, you use -> to access it's members, if it's just a regular variable you use .

struct test{
int x;
};

test tVar;
test* tpVar;

tVar.x = 5; //yes

tpVar.x = 5; //no
tpVar->x = 5; //yes
(*tpVar).x = 5 // yes

[abdul]

I have read about pointers but just forgot a bit so
Can you explain the examples which you gave me (a kind of another approach) because i did not understand the "struct" and then a bracket and then "You have declared a variable"
Can you explaim me please that what is happening in that example


That would be really helpfull

[Vlatko]

In fact, an expression involving the member-selection operator (->) is a shorthand version of an expression using the period (.) if the expression before the period consists of the indirection operator (*) applied to a pointer value. Therefore,

expression -> identifier

is equivalent to

(*expression) . identifier

when expression is a pointer value.