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javascriptfunctionecmascript-6

Function declaration is block scoped

It is said that function declarations are block-scoped but the code below cause confusion in my mind. Please if anybody knows some article which reflects the true behaviour of function declaration.

{ // Enter a new scope

  console.log(foo()); // prints hello
  function foo() {
    return 'hello';
  }

}
foo(); // {A} // prints "hello"

If functions would have been block-scoped then why should line {A} have printed "hello" in console.

Solution

  • Problem with the code above is that it ran in sloppy mode, thats why everything went well. But in strict mode line A will return error. Hence, functions are block-scoped.

    'use strict';
{ // Enter a new scope

  console.log(foo()); // prints hello
  function foo() {
    return 'hello';
  }

}
foo(); // {A} // throws error