What are the differences between methods of constructing an object

Consider the 3 ways of constructing an object:

1)

LogTreeItem::LogTreeItem(const QList<QVariant>& data, LogTreeItem* parent) :
    m_parentItem {parent}, m_itemData {data}
{
}

2)

LogTreeItem::LogTreeItem(const QList<QVariant>& data, LogTreeItem* parent) :
    m_parentItem (parent), m_itemData (data)
{
}

3)

TreeItem::TreeItem(const QList<QVariant> &data, TreeItem *parent)
{
    m_parentItem = parent;
    m_itemData = data;
}

Are they 100% equal? if not, where they differ? what are any advantage/disadvantage associated with each method?

I am guessing some stuff about copy assignment, move constructor or some advanced things in modern c++11 and beyond is getting done in case of 1 and 2.