How to expand to Parent Widget width?

This is always asked by the people, how to extend widget to its parent, so I thought of writing one blog which has all this.

The correct solution would be to use the SizedBox.expand widget, which enforces its child to match its parent's size.

SizedBox.expand(
  child: RaisedButton(...),
)

Using SizeBox

SizedBox(
  width: double.infinity,
  // height: double.infinity,
  child: RaisedButton(...),
)

Using ConstrainedBox

ConstrainedBox(
    constraints: const BoxConstraints(minWidth: double.infinity),
    child: RaisedButton(...),
)

Using Container

Containershould be used when we required other properties of it, otherwise, we should avoid and use SizeBox

Container(
  width: double.infinity,
  // height: double.infinity,
  child: RaisedButton(...),
)