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How do I check for null values in JavaScript?
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Javascript is very flexible with regards to checking for "null" values. I'm guessing you're actually looking for empty strings, in which case this simpler code will work:
if(!pass || !cpass || !email || !cemail || !user){
Which will check for ...
What is the equivalent of the C# 'var' keyword in Java?
...yword in C# is implicit type declaration. What is the Java equivalent syntax for var ?
15 Answers
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Retina displays, high-res background images
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Do I need to double the size of the .box div to 400px by 400px to
match the new high res background image
No, but you do need to set the background-size property to match the original dimensions:
@media (-webkit-min-device-pixel-ratio: 2),
(min-resolution: 1...
Why use Abstract Base Classes in Python?
... EAFP or type introspection to confirm that the unknown object meets this expected contract.
But there are also higher-level, semantic promises in the contract.
For example, if there is a __str__() method, it is expected to return a string representation of the object. It could delete all contents o...
Why does pylint object to single character variable names?
... and not too short.
You can use this to avoid such short names:
my_list.extend(x_values)
Or tweak PyLint's configuration to tell PyLint what variable name are good.
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wpf: how to show tooltip when button disabled by command?
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This goes in the xaml declaration for the object on which the tooltip will appear, i.e.: <Button ToolTipService.ShowOnDisabled="True">...
– gusmally supports Monica
Nov 4 '19 at 18:44
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Convert an enum to List
... @DCShannon please do not edit popular questions/answers and shrink explanations. While you and I understand shorthand code, newbie's need all the extra details to associate it with their learnings.
– Jeremy Thompson
Sep 23 '14 at 9:16
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Some questions about Automatic Reference Counting in iOS5 SDK
...ect retain]
and [myObject release] statements from
my code?
Yes, but XCode 4.2 includes a new "Migrate to Objective-C ARC" tool (in the Edit->Refactor menu), which does that for you. Calling dealloc is a different story. As mentioned in the comments the clang reference states that you shoul...
How to detect orientation change?
... edited Oct 11 '19 at 12:43
Xavier Lowmiller
1,13911 gold badge1515 silver badges2121 bronze badges
answered Sep 4 '14 at 13:59
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public static const in TypeScript
...s this TS snippet compiled into (via TS Playground):
define(["require", "exports"], function(require, exports) {
var Library = (function () {
function Library() {
}
Library.BOOK_SHELF_NONE = "None";
Library.BOOK_SHELF_FULL = "Full";
return Library;
})...