How to use onClick() or onSelect() with option tag? Below is my code in which I tried to implement that, but it is not working as expected. Note: where listCustomer domain object list getting in JSP page. How do I modify it to detect that an option is selected? Answer Neither the onSelect() nor onClick() events are supported by the
Best way to convert string to array of object in javascript?
I want to convert below string to an array in javascript. How do I convert this string into array of objects? Any cool idea? Answer I think that the best way of doing this, as Douglas Crockford (one of the biggests gurus of JavaScript) suggests in here is using the JSON native parser, as it is not only faster than
How to append to a file in Node?
I am trying to append a string to a log file. However writeFile will erase the content each time before writing the string. Any idea how to do this the easy way? Answer For occasional appends, you can use appendFile, which creates a new file handle each time it’s called: Asynchronously: Synchronously: But if you append repeatedly to the same
How do you use window.postMessage across domains?
It seems like the point of window.postMessage is to allow safe communication between windows/frames hosted on different domains, but it doesn’t actually seem to allow that in Chrome. Here’s the scenario: Embed an <iframe> (with a src on domain B*) in a page on domain A The <iframe> ends up being mostly a <script> tag, at the end of which’s
How to scale an imageData in HTML canvas?
I have a canvas in my webpage; I create a new Image data in this canvas then I modify some pixel through myImgData.data[] array. Now I would like to scale this image and make it bigger. I tried by scaling the context but the image remains small. Is it possible to do this? Thanks Answer You could draw the imageData
Comparing negative numbers in javascript
I’m sure this is a simple problem, but I’m comparing negative numbers in javascript i.e.: This script will always take action 2, even though num1 is less than num2. Whats going on here? Answer How does if (parseFloat(num1) < parseFloat(num2)) work? Maybe your numbers are turning into strings somewhere.
JavaScript, Generate a Random Number that is 9 numbers in length
I’m looking for an efficient, elegant way to generate a JavaScript variable that is 9 digits in length: Example: 323760488 Answer You could generate 9 random digits and concatenate them all together. Or, you could call random() and multiply the result by 1000000000: Since Math.random() generates a random double precision number between 0 and 1, you will have enough digits
jQuery: how to change tag name?
jQuery: how to change tag name? For example: I need Yes, I can Create DOM element <div> Copy tr content to div Remove tr from dom But can I make it directly? PS: results in DOMException. Answer You can replace any HTML markup by using jQuery’s .replaceWith() method. example: http://jsfiddle.net/JHmaV/ Ref.: .replaceWith If you want to keep the existing markup,
JavaScript Integer math incorrect results
I am just trying to implement a simple RNG in JS. What’s happening is javascript evaluates 119106029 * 1103515245 to be 131435318772912110 rather than 131435318772912105. We know it’s wrong since two odd numbers multiplied does not give an even number. Anyone know what’s up? I just want a reliable repeatable RNG, and because of these incorrect values I can’t get
How to get first character of string?
I have a string, and I need to get its first character. How can I fix my code? Answer charAt can give wrong results for Unicode. Use Array.from: