javascript How does the double exclamation (!!) work in javascript?

https://stackoverflow.com/questions/784929/what-is-the-not-not-operator-in-javascript

https://stackoverflow.com/questions/29312123/how-does-the-double-exclamation-work-in-javascript

value	!value	!!value
false	true	false
true	false	true
null	true	false
undefined	true	false
0	true	false
-0	true	false
1	false	true
-5	false	true
NaN	true	false
''	true	false
'hello'	true	false