Pass a label and an onClick callback into the IconButton below from a parent. Then call it from Toolbar with two different labels.

Name three reasons React tends to win over older imperative DOM frameworks. One sentence each.

Build a <Toggle> render-prop component that owns boolean state and lets its caller render any UI it wants. The caller should be able to render either a checkbox or a button using the same <Toggle>.

Two sibling components need to share the same query string. Without using Context or a global store, where should that state live, and why? Sketch the fix.