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JavaScript DOM remove element
I'm trying to test if a DOM element exists, and if it does exist delete it, and if it doesn't exist create it.
5 Answers
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select * vs select column
If I just need 2/3 columns and I query SELECT * instead of providing those columns in select query, is there any performance degradation regarding more/less I/O or memory?
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C# Java HashMap equivalent
Coming from a Java world into a C# one is there a HashMap equivalent? If not what would you recommend?
7 Answers
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Skip download if files exist in wget?
...oading of the file. It just doesn't do anything after downloading the file if the file has already been fully retrieved. Is there anyway to prevent making the HTTP request if the file already exists? stackoverflow.com/questions/33203898/…
– ma11hew28
Oct 18 '...
How can I check whether an array is null / empty?
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There's a key difference between a null array and an empty array. This is a test for null.
int arr[] = null;
if (arr == null) {
System.out.println("array is null");
}
"Empty" here has no official meaning. I'm choosing to define empty a...
Ruby, !! operator (a/k/a the double-bang) [duplicate]
...y, the only two things that evaluate to false are false (itself) and nil.
If you negate something, that forces a boolean context. Of course, it also negates it. If you double-negate it, it forces the boolean context, but returns the proper boolean value.
For example:
"hello" #-> this is a s...
Can you have if-then-else logic in SQL? [duplicate]
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You can make the following sql query
IF ((SELECT COUNT(*) FROM table1 WHERE project = 1) > 0)
SELECT product, price FROM table1 WHERE project = 1
ELSE IF ((SELECT COUNT(*) FROM table1 WHERE project = 2) > 0)
SELECT product, price FROM table1 WHER...
AngularJS : Why ng-bind is better than {{}} in angular?
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If you are not using ng-bind, instead something like this:
<div>
Hello, {{user.name}}
</div>
you might see the actual Hello, {{user.name}} for a second before user.name is resolved (before the data is loaded)...
Syntax for if/else condition in SCSS mixin
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You could try this:
$width:auto;
@mixin clearfix($width) {
@if $width == 'auto' {
// if width is not passed, or empty do this
} @else {
display: inline-block;
width: $width;
}
}
I'm not sure of your intended result, but setting a default value should retu...
Type definition in object literal in TypeScript
...n object literal, not an class object. Also an interface can have methods. If your interface defines a method, then the object literal must also define it - it won't be null. The object literal must fulfill everything the the interface defines or the type system will show an error.
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