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<html><body><h2>JavaScript Errors</h2><p>You cannot use the value of a non-existing variable:</p><p id="demo"></p><script>let x = 5;try { x = y + 1;}catch(err) { document.getElementById("demo").innerHTML = err.name;}</script></body><!-- Mirrored from www.w3schools.com/js/tryit.asp?filename=tryjs_error_referenceerror by HTTrack Website Copier/3.x [XR&CO'2014], Mon, 05 Sep 2022 14:46:47 GMT --></html>