As someone who likes working with higher level languages, I never understood the pass by reference or even referencing different pointers. It never stuck out to me as useful in what I want software to do. It’s too close to hardware.
Most of the time you pass by reference for more outputs, or by const ref to avoid copying a big-ass data structure (which is not always straightforward, with structures smaller than a pointer, which are pretty big in 64 bits architecture, you lose more to the ref overhead than to the copy IIRC)
if you’re working with higher level languages you pass-by-reference all the time. give a list to a function to modify it? that’s by reference. giving an event handler function to a framework? that’s by reference. setting a property on an object? that’s usually by reference.
Your example doesn’t make sense to me. Why would you modify the entire list by checking if something is in it? Also, you can totally edit the list via a pointer, that’s how you’re supposed to edit the list if you want any performance. Otherwise you’d be copying the list on every modification, which is terribly inefficient
A pointer to the list would allow you to modify whatever’s at that pointer’s address though. If you want to look at the list and not edit it you pass by const reference 99% of the time (or you pass a copy) and if your language doesn’t have that I don’t like it.
I want my language to pass by reference. I give a variable to a function and the variable in the function scope should be a reference to the same place in memory as the original variable.
How can pointers help me here? What value does it provide? Genuine question.
I want my language to pass by reference. I give a variable to a function and the variable in the function scope should be a reference to the same place in memory as the original variable.
I’m not even a C++ wizard or anything (though it’s my most advanced language) so I’m not gonna argue that is good or bad, that sounds fine to me for a wide range of applications already.
But the way is see it, pointers kinda allow you to use “raw memory” which is an actual thing that’s gonna be handled by the program one way or another, and it’s a way to relatively refer to memory for example. As some guy on stackoverflow put it “That guy at the end for the bar” vs “Bob” can be very useful. Especially when using data structures you don’t know the size of at compile time.
The
&operator references the value.In C++, the
&at the function argument makes it a reference type (safe pointer).void someFunction(int& refVal) { [...] }As someone who likes working with higher level languages, I never understood the pass by reference or even referencing different pointers. It never stuck out to me as useful in what I want software to do. It’s too close to hardware.
Most of the time you pass by reference for more outputs, or by const ref to avoid copying a big-ass data structure (which is not always straightforward, with structures smaller than a pointer, which are pretty big in 64 bits architecture, you lose more to the ref overhead than to the copy IIRC)
Another reason I commonly see: to change the structure / “main pointer” to a data structure (esp during freeing and cleanup).
if you’re working with higher level languages you pass-by-reference all the time. give a list to a function to modify it? that’s by reference. giving an event handler function to a framework? that’s by reference. setting a property on an object? that’s usually by reference.
the list is the helpful part to understanding it.
it would be terrible if, with bar being a list and foo being a member of the list
modified the list. So yeah, you want to look at the list not edit the list, it’s a pointer.
Your example doesn’t make sense to me. Why would you modify the entire list by checking if something is in it? Also, you can totally edit the list via a pointer, that’s how you’re supposed to edit the list if you want any performance. Otherwise you’d be copying the list on every modification, which is terribly inefficient
other way round surely? if you want to modify the original object, use a pointer. if you don’t, use a copy.
A pointer to the list would allow you to modify whatever’s at that pointer’s address though. If you want to look at the list and not edit it you pass by const reference 99% of the time (or you pass a copy) and if your language doesn’t have that I don’t like it.
I still don’t get the point of pointers.
I want my language to pass by reference. I give a variable to a function and the variable in the function scope should be a reference to the same place in memory as the original variable.
How can pointers help me here? What value does it provide? Genuine question.
I’m not even a C++ wizard or anything (though it’s my most advanced language) so I’m not gonna argue that is good or bad, that sounds fine to me for a wide range of applications already.
But the way is see it, pointers kinda allow you to use “raw memory” which is an actual thing that’s gonna be handled by the program one way or another, and it’s a way to relatively refer to memory for example. As some guy on stackoverflow put it “That guy at the end for the bar” vs “Bob” can be very useful. Especially when using data structures you don’t know the size of at compile time.
Reference values are quite useful, such as: