CODEWITHSUNDEEP
javascript
sparkhoom
sparkhoom

Reputation: 1

can't change the a variable value in the javascript function

I am new to Javascript, I am confused about the code below for hours. I wanna know why i can't assign the value of result to htmlContent. Thanks!

var htmlContent = fs.readFileSync(program.file);

restler.get('http://google.com').on('complete', function(result) {
    if (result instanceof Error) {
        util.puts('Error: ' + result.message);
    } else {
       htmlContent = result;
    }
});
console.log(htmlContent);

Upvotes: 0

Views: 101

Answers (3)

schnill
schnill

Reputation: 955

Here, your function inside the .on() will be called asynchronously (in simple words it will get executed when "complete" event occurs i.e. some later time) and you are using console.log(htmlContent) is regular function call, so you can not set htmlContent value inside the function this way.

If you want to use result value in any other function then you should pass this value to your next function. I hope this will work.

Upvotes: 0

Rhys Butler
Rhys Butler

Reputation: 1

I would look up the concept of futures and promises in JS, this might help clear up some fundamentals: http://monochrome.sutic.nu/2012/04/06/javascript-futures.html

When you are using continuations in JS (a requirement in node.js especially), you really need to get your head around them.

Upvotes: 0

wavebeem
wavebeem

Reputation: 73

The problem here is that the line starting with restler.get begins before the console.log, but it doesn't finish before it necessarily.

You should put your console.log inside the restler.get call.

Upvotes: 2

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