troubleshooting Question

Double Exclamation Marks

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steva asked on
JavaScript
4 Comments1 Solution505 ViewsLast Modified:
I came across the line below is some code I was looking at.  Does anyone know what the double exclamation marks mean?

var w3cEventModel = !!document.addEventListener;


Thanks
Steve
ASKER CERTIFIED SOLUTION
leakim971
Multitechnician
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