Qt About using layouts, widget parenting


The layouts are a necessary in every Qt application. They manage the object, their position, their size, how they are resized.


From Qt layout documentation:

When you use a layout, you do not need to pass a parent when constructing the child widgets. The layout will automatically reparent the widgets (using QWidget::setParent()) so that they are children of the widget on which the layout is installed.

So do :

QGroupBox *box = new QGroupBox("Information:", widget);

or do :

QGroupBox *box = new QGroupBox("Information:", nullptr);

is exactly the same.