tracker.sqf

[{
    {
        // _x is a variable that contains a merlin from the list after "forEach"
        // The code in this loop will run 6 time, each time _x will change to the next one, starting with merlin1 and ending with merlin6
        
        // _forEachIndex is the current index in the loop, it's just a number basically
        // First iteration on merlin1 would make it 0, when it gets to merlin6 it will be 5 (notice that it doesn't start at 1)
        
        // The command "private" makes the given variable only available to the current scope
        // Doing this means _marker and _randPos aren't available to be used outside of the loop
        // It's somewhat optional in this case, but it's good practice
        
        // The command "format" is just for string concatenation
        // %1 is an indicator to the command that the first value should be placed here, in this case it's _forEachIndex
        // Each iteration of the loop, you're left with "Marker0" up to "Marker5"
        
        private _marker = format ["Marker%1", _forEachIndex];
        private _randPos = [_x, 50] call CBA_fnc_randPos;
        
        if (alive _x) then {
            _marker setMarkerPos _randPos;
        } else {
            deleteMarker _marker;
        };
    } forEach [merlin1, merlin2, merlin3, merlin4, merlin5, merlin6];
}, 60, []] call CBA_fnc_addPerFrameHandler;