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<title>JavaScript strict mode enable globally</title>
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<pre> <!-- Use pre element for work document.writeln() method -->
<script type="text/javascript">
"use strict";
var var1 = 10; // works
document.writeln(var1);
function myFun(){
"use strict";
var var2 = 15; // works
document.writeln(var2);
}
myFun();
// Remove below comments and run it again it will throw syntax error
// var3 = 10; // undefined
document.writeln(var3);
</script>
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