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How do I test for an empty JavaScript object?
...ome additional check
Object.keys(obj).length === 0 && obj.constructor === Object
Note, though, that this creates an unnecessary array (the return value of keys).
Pre-ECMA 5:
function isEmpty(obj) {
for(var prop in obj) {
if(obj.hasOwnProperty(prop)) {
return false;
}
}
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PHP 5.4 Call-time pass-by-reference - Easy fix available?
Is there any way to easily fix this issue or do I really need to rewrite all the legacy code?
3 Answers
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Definition of a Balanced Tree
...ing if someone might be able to clarify the definition of a balanced tree for me. I have that "a tree is balanced if each sub-tree is balanced and the height of the two sub-trees differ by at most one.
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What are the differences between vector and list data types in R?
What are the main differences between vector and list data types in R? What are the advantages or disadvantages of using (or not) these two data types?
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Public Fields versus Automatic Properties
...tect encapsulation by making getter and setter methods (properties in C#) for class fields, instead of exposing the fields to the outside world.
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How do I make a column unique and index it in a Ruby on Rails migration?
...
The short answer for old versions of Rails (see other answers for Rails 4+):
add_index :table_name, :column_name, unique: true
To index multiple columns together, you pass an array of column names instead of a single column name...
How do I fix certificate errors when running wget on an HTTPS URL in Cygwin?
For example, running wget https://www.dropbox.com results in the following errors:
9 Answers
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Convert Int to String in Swift
I'm trying to work out how to cast an Int into a String in Swift.
22 Answers
22
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Citing the author of a blockquote using Markdown syntax
I am using the Symfony CMS and it uses Markdown for article writing. I need to do a blockquote of a quote from Benjamin Franklin and would like to have the quote followed by a citation beneath it, but right now all it does is blockquote the whole line. How does one do this in markdown syntax?
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Test whether a Ruby class is a subclass of another class
...ass inherits from another class, but there doesn't seem to exist a method for that.
2 Answers
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