Structures and pointers question

If I have the structure below:

Code:

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    10 struct
    11      {
    12        int cin;
    13        int mo;
    14        int next_step;
    15        int tested_cin;
    16      } coil_info;

---

and in SQL declare it states:

Code:

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    335        EXEC SQL BEGIN DECLARE SECTION;
    336          coil_info coil;
    337        EXEC SQL END DECLARE SECTION;

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when (&coil) and (coil) is passed to functions like below what is the difference between the two?

update_coil(coil)
then using coil->cin

update_coil(&coil)
then using coil->cin

The two would have the same value correct?

One passed address of pointer and other address of the actual data? I see no difference. Any help is appreciated.

coil IS the struct, while &coil is its address. coil is not in any way, shape, or form an address. coil->cin should not compile.

Quote:

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update_coil(coil)
then using coil->cin

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You only pass a copy of the object coil: the value of cin after the call is still
the same value than before the call.

Quote:

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update_coil(&coil)
then using coil->cin

---

This time you pass the object itself (through its address) so the function
can modify its content: cin contains the updated value after the call.