The boolean type variable is used in control-flow, which we will get to in the next section.
The two types it may hold are
Usually you don't declare a variable, but you rather use an expression that evaluates to a boolean value - true or false.
nullsimply means nothing. It represents and evaluates to false. However, this does not mean it's empty.
var myVariable = ''; // myVariable is empty, but not null.
undefined means a variable that hasn't yet contained a value.
Stretch out your back and relieve your back muscles with inversion therapy. This device counteracts the forces of gravity on the body by decompressing and elongating the spine. By using this product just ten minutes a day, you can be well on your way to improved circulation and posture while relieving muscle aches, back pain and stress.$$ Check price