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Re: Can somebody explain this code

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On 23/03/16 20:46, Tony Mountifield wrote:
> In article <ncv2un$mlp$1@dont-email.me>,
> Tony Johansson <johansson.andersson@telia.com> wrote:
>> I know that functions behave much like variables such as
>> var myFunc = function() { alert("This is my anonymous function");}
>>
>> But in the code below when I have (a && b)(); only function b is called and
>> when I have  (a || b)();  only function a is called
>>
>> If a = null in this example (a || b)();   then b is called.
>>
>> Can somebody explain what is happening here when I have this kind of strange 
>> looking code.
>> I do this just because of some testing how it works.
>>
>> If both a and b is null I get error because then the expression does not 
>> produce a function value which is correct.
>>
>> <script type="text/javascript">
>>         function a()
>>         {
>>             alert("function a");
>>         };
>>
>>         function b()
>>         {
>>             alert("function b");
>>         };
>>
>>        (a && b)(); //here only b is called
> 
> The expression (a && b) returns a if a is not truthy, but returns b if a is truthy.
> In this case a and b are pointers to functions, which are always truthy. So (a && b)
> has the value b, which is then called by virtue of the following ().
> 
>>         (a || b)(); // here only a is called
> 
> The expression (a || b) returns a if a is truthy, otherwise returns b. So (a || b)
> always has the value a when a is a function pointer, and this gets called by the ().
> 
>>     </script>
>>
>> //Tony 
> 
> Cheers
> Tony (another one!)

Truthy, eh?  lol

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Re: Can somebody explain this code tony@mountifield.org (Tony Mountifield) - 2016-03-23 23:46 +0000
  Re: Can somebody explain this code Aleksandro <aleksandro@gmx.com> - 2016-03-23 23:58 -0300
  Re: Can somebody explain this code Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-24 04:20 +0100
    Re: Can somebody explain this code "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2016-03-24 11:23 +0100
      Re: Can somebody explain this code Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-03-24 20:32 +0100
    Re: Can somebody explain this code John Harris <niam@jghnorth.org.uk.invalid> - 2016-03-24 11:22 +0000

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