For example I have an vector of objects and they all have attribute PointX so I want to check if all of them have the same value of PointX and if they have it should return true or false whatever.
So in a kind of pseudo-code:
IF ( Object[1].getPointX() == Object[2].getPoint(x) == Object[3].getPoint(x) ){
return true;
}
The problem is that I have more than 55 objects so there has to be a way to compare them without writting them all individually. I know there must be with a for loop but still I have no idea.
thanks in advance.
edit: @awesomeyi your suggestion seems the easiest and more adequate to my needs (I'm not saying the others are not but I think they are too complicated for a newb like me) but it's not working, even if Xpoints are all the same or different it always returns false. here's what i have:
bool allKilled(){
auto checkpointx = Invader[0].getIfActive();
for(int i = 0; i < 55; ++i){
if(Invader[i].getIfActive() != checkpointx){
return false;}
}
}
the getIfActive() just returns if its true or false, and i want this method to return true if all Active (attribute of the object) of all objects are all false.
Something like this:
auto refx = Object[0].getPointX();
bool b = std::all_of(Object.begin(),
Object.end(),
[refx](TheTypeOfTHeElements& e)
{ return e.getPointX() == ref; });
Obviously you need to check that Objects
is not empty.
For loop?
auto checkpointx = Object[0].getPointX();
for(int i = 1; i < Object.size(); ++i){
if(Object[i].getPointX() != checkpointx)
return false;
}
I'd do it something like this:
template<typename Objects, typename Comparison>
bool is_all_same( Objects&& objects, Comparison&& comp ) {
using std::begin; using std::end;
auto&& b = begin(objects);
auto&& e = end(objects);
if (b == e)
return true;
auto&& first = *b;
for( auto&& cur = std::next(first); cur != e; ++cur ) {
if (!comp( first, cur ))
return false;
}
return true;
}
use:
bool all_same_x = is_all_same( objs, []( Obj const& left, Obj const& right )->bool {
return left.getPointX() == right.getPointX();
});
where objs
is some container or range containing objects of type Obj
.
The above code should work on all standard containers, C style arrays, custom containers that support the new for loops, and is close to optimal performance wise.
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