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Difference between freeze and seal
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@AlanDong A bit late in coming, but here is why you want to lock down an object.One of JavaScript’s features is that you can add a property any time you like; you can also do this accidentally by mis-typing. Many of my students have tr...
How to check if a string in Python is in ASCII?
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@wjandrea Yeah, obviously, but because 0x03 fits in 7 bits doesn't mean that it's what most people will want to be checking for when they find this page in their search results.
– Luc
Jul 13 at 18:24
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IIS7 Cache-Control
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Note that max-age is a delta in seconds, being expressed by a positive 32bit integer as stated in RFC 2616 Sections 14.9.3 and 14.9.4. This represents a maximum value of 2^31 or 2,147,483,648 seconds (over 68 years). However, to better ensure compatibility between clients and servers, we adopt a r...
Understand homebrew and keg-only dependencies
I've recently started using homebrew, and I'm a bit confused as to what happens when I brew something onto my system, but its brewed dependencies are keg-only, meaning that they are linked under /usr/local .
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When writing a directive in AngularJS, how do I decide if I need no new scope, a new child scope, or
...ever, I required a set of data to use and additionally had to store a tiny bit of state. In this case, using the parent scope would be irresponsible (again, generally speaking). So instead...
Child Scope: scope: true
Directives with a child scope are context-aware and are intended to interact with...
Difference between SurfaceView and View?
...ified by the UI Thread. With most games, SurfaceViews will be doing a good bit of rendering which would block up the UI Thread with a simple view. That is the primary benefit, from my understanding, of a SurfaceView.
– zgc7009
Feb 25 '15 at 15:57
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How to Sort Multi-dimensional Array by Value?
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My phrasing is a little bit off, I'll edit it. What I meant is that if you're not on PHP 5.3, you need to create a special function just for this particular sorting (Which is somehow not very elegant). Otherwise you could use an anonymous function r...
Difference between case object and object
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Case classes differ from regular classes in that they get:
pattern matching support
default ...
JavaScript null check
... = null;
alert(a === null); // true
As @rynah mentions, "undefined" is a bit confusing in JavaScript. However, it's always safe to test if the typeof(x) is the string "undefined", even if "x" is not a declared variable:
alert(typeof(x) === 'undefined'); // true
Also, variables can have the "un...
Detect when an image fails to load in Javascript
...steners as you want on the same event.
Let me rewrite the answer a little bit.
function testImage(url) {
var tester = new Image();
tester.addEventListener('load', imageFound);
tester.addEventListener('error', imageNotFound);
tester.src = url;
}
function imageFound() {
alert('T...