Databases
StackOverflow2013
Postsdbo
POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
    primarykey
    data
    text
    <p>I am a little confused as to how passing pointers works.</p> <p>Let's say I have the following function and pointer, and... </p> <p><strong>EDIT</strong>: </p> <p>...I want to use a pointer to some object as an argument in the function.</p> <p>i.e.:</p> <pre><code>void Fun(int Pointer){ int Fun_Ptr = ---Passed Pointer---; //So that Fun_Ptr points to whatever ---Passed Pointer points to </code></pre> <p>Between the *Pointer and &amp;Pointer notations, I am very confused. I know that *Pointer means give whatever it points to.</p> <p>Do I put void (int *pointer) in the declaration. What about when I use the function?</p> <p>Your assistance is appreciated.</p> <p><strong>EDIT 2:</strong></p> <p>Okay, I now understand that using *variable in a declaration means that a pointer will be passed. However, what about when i use the function?</p> <p>i.e.</p> <pre><code>int main(){ int foo; int *bar; bar = foo; Fun(bar); } </code></pre> <p><strong>EDIT 3:</strong> Okay, so correct me if I am wrong:</p> <p>According to the conventions of the above code:</p> <p>bar = &amp;foo means: Make bar point to foo in memory</p> <p>*bar = foo means Change the value that bar points to to equal whatever foo equals</p> <p>If I have a second pointer (int *oof), then:</p> <p>bar = oof means: bar points to the oof pointer</p> <p>bar = *oof means: bar points to the value that oof points to, but not to the oof pointer itself</p> <p>*bar = *oof means: change the value that bar points to to the value that oof points to</p> <p>&amp;bar = &amp;oof means: change the memory address that bar points to be the same as the memory address that oof points to</p> <p>Do I have this right?</p> <p>EDIT 4: Thanks so much for all your help (I wish I could accept more than 1 answer, but I have to go with the first one. I am not sure how a community wiki works exactly, but I will leave it this way for editing (feel free to turn it into a ref guide if you like).</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USBiosci3c
    1. USBiosci3c
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
      1. USminimalpop
      1. VTFavorite
    2. VO
      singulars
      1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
      1. USaugustin
      1. VTFavorite
    3. VO
      singulars
      1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
      1. This table or related slice is empty.
      1. VTUpMod
    1. COYour second edit is nearly correct, however
      singulars
      1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
      1. USTomas
    2. CO"Is that correct?". No. You do not want `bar` to be *equal* to `foo`, you want it to *point to* `foo`. This is done with the address-of operator. `bar = &foo;`.
      singulars
      1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
      1. USSteve Jessop
    3. CObar = foo, is invalid, as foo is an int and bar a pointer. The correct code is "bar = &foo" because as a pointer, bar can only store memory addresses not an int. Sorry for the comment answers.
      singulars
      1. POC++ Passing Pointer to Function (Howto) + C++ Pointer Manipulation
      1. USTomas
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload