123 lines
3.6 KiB
Markdown
123 lines
3.6 KiB
Markdown
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# AddArray
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Adds elements from one array to the end of another.
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```
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bool AddArray(
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const CArrayObj * src // pointer to the source array
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)
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```
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Parameters
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src
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[in] Pointer to an instance of the [CArrayDouble](/en/docs/standardlibrary/datastructures/carraydouble) class - source of elements to add.
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Return Value
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true - successful, false - cannot add items.
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Note
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Adding elements from array to array is actually copying the pointers. Therefore, when calling the method, there is a pitfall - there may be a pointer to a dynamic object in more than one variable.
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```
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//--- example
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extern bool make_error;
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extern int error;
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extern CArrayObj *src;
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//--- create a new instance CArrayObj
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//--- default memory management is turned on
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CArrayObj *array=new CArrayObj;
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//--- add (copy) the elements from the source array
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if(array!=NULL)
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bool result=array.AddArray(src);
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if(make_error)
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{
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//--- perform erroneous actions
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switch(error)
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{
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case 0:
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//--- remove the source array without checking its memory management flag
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delete src;
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//--- result:
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//--- it is possible to address an element by invalid pointer in the receiver array
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break;
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case 1:
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//--- disable the mechanism of memory management in the source array
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if(src.FreeMode()) src.FreeMode(false);
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//--- but do not remove the source array
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//--- result:
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//--- after removing the receiver array, it is possible to address an element by invalid pointer in the source array
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break;
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case 2:
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//--- disable the mechanism of memory management in the source array
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src.FreeMode(false);
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//--- disable the mechanism of memory management in the receiver array
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array.FreeMode(false);
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//--- result:
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//--- after the program termination, get a "memory leak"
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break;
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}
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}
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else
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{
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//--- disable the mechanism of memory management in the source array
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if(src.FreeMode()) src.FreeMode(false);
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//--- delete the source array
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delete src;
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//--- result:
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//--- addressing the receiver array element will be correct
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//--- deleting the receiver array will lead to deleting its elements
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}
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```
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Example:
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```
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//--- example for CArrayObj::AddArray(const CArrayObj*)
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#include <Arrays\ArrayObj.mqh>
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//---
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void OnStart()
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{
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CArrayObj *array=new CArrayObj;
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//---
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if(array==NULL)
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{
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printf("Object create error");
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return;
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}
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//--- create source array
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CArrayObj *src=new CArrayObj;
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if(src==NULL)
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{
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printf("Object create error");
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delete array;
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return;
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}
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//--- reset free mode flag
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src.FreeMode(false);
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//--- fill source array
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//--- . . .
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//--- add another array
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if(!array.AddArray(src))
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{
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printf("Array addition error");
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delete src;
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delete array;
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return;
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}
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//--- delete source array without elements
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delete src;
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//--- use array
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//--- . . .
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//--- delete array
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delete array;
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}
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```
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