How to set size on an array post compile

[SinaSyndrome]

Hello,
I'm new to this website and I am pretty excited to be a part of this community now.
I am taking my second course in c++ right now and I have this problem where i need to find a way to ask the user to input a number and that number will be set as the size of the array. I know i'm suppose to implement pointers in some way but i'm having trouble with it. Any tips?

void GetInfo(const int* numStudents)
{

const int *numStudents;
int y;
cout <<"enter amount of students:" << endl;
cin >> y;
numStudents = &y;
school[*numStudents];
//numStudents = school[];
schoolArrayInput(school, *numStudents);
}

Here is my code so far.

[Callum5042]

Sounds like you need to use dynamic memory, here a link below.

http://www.cplusplus.com/doc/tutorial/dynamic/

Also, I don't see that you have declared any arrays.

[AbstractionAnon]

void GetInfo(const int* numStudents)
{

const int *numStudents;
int y;
cout <<"enter amount of students:" << endl;
cin >> y;
numStudents = &y;
school[*numStudents];
//numStudents = school[];
schoolArrayInput(school, *numStudents);
}

Line 4: numStudents has already been declared as an argument.
Line 9: Are you trying to declare any array? You need a type and a name. You have only one of the two (not sure which). Also, you can't declare any array with a variable.

PLEASE USE CODE TAGS (the <> formatting button). Code tags make it easier to help you.

[SinaSyndrome]

Thanks for the help.

sorry I did not put the entire code up.
on line 9. school is the type i made using a structure. it contains 3 variables of type double.
I;m going to try to correct the code and see what happens.

[Framework]

SinaSyndrome wrote:

"I have this problem where i need to find a way to ask the user to input a number and that number will be set as the size of the array."

This is not possible. An array's length must be constant and known during a declaration context. Some compilers, such as GCC, support non-constant array lengths as an extension, however. To create an array during run-time, you will need to reserve memory from the heap. Here's an example:

int main( )
{
    int Value_(0);
    std::cin >> Value_; // Get the length of the array.
    
    int *Memory_(0x0);
    if(Value_ > 0)
        Memory_ = new int[Value_];

    // We're done with the memory.
    delete [] Memory_;
    return(0);
}

See here for further details: http://www.cplusplus.com/doc/tutorial/dynamic/

_Wazzak

[helios]

An array's length must be constant and known during a declaration context. Some compilers, such as GCC, support non-constant array lengths as an extension, however.

Framework is talking about arrays residing on the stack and in static memory (e.g. global arrays are static), not about arrays in general.