This code will output 5 despite seeming as if the variable was declared within a function and can't be accessed outside of it. This is because

1var a = b = 5;

is interpreted the following way:

1var a = b;
2b = 5;

But b is not declared anywhere in the function with var so it is set equal to 5 in the global scope.

Source

• https://coderbyte.com/algorithm/10-common-javascript-interview-questions

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(function() {

  var a = b = 5;

})();

​

console.log(b);