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What reason is there to use null instead of undefined in JavaScript?
I've been writing JavaScript for quite a long time now, and I have never had a reason to use null . It seems that undefined is always preferable and serves the same purpose programmatically. What are some practical reasons to use null instead of undefined ?
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What do 3 dots next to a parameter type mean in Java?
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It means that zero or more String objects (or a single array of them) may be passed as the argument(s) for that method.
See the "Arbitrary Number of Arguments" section here: http://java.sun.com/docs/books/tutorial/java/javaOO/arguments.html#varargs
In your exa...
Compare two files line by line and generate the difference in another file
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diff(1) is not the answer, but comm(1) is.
NAME
comm - compare two sorted files line by line
SYNOPSIS
comm [OPTION]... FILE1 FILE2
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-1 suppress lines unique to FILE1
-2 suppress lines unique to FILE2
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How do you remove duplicates from a list whilst preserving order?
Is there a built-in that removes duplicates from list in Python, whilst preserving order? I know that I can use a set to remove duplicates, but that destroys the original order. I also know that I can roll my own like this:
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Most efficient way to prepend a value to an array
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I'm not sure about more efficient in terms of big-O but certainly using the unshift method is more concise:
var a = [1, 2, 3, 4];
a.unshift(0);
a; // => [0, 1, 2, 3, 4]
[Edit]
This jsPerf benchmark shows that unshift is decently fas...
How do I check if an index exists on a table field in MySQL?
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Use SHOW INDEX like so:
SHOW INDEX FROM [tablename]
Docs: https://dev.mysql.com/doc/refman/5.0/en/show-index.html
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How to compare only date components from DateTime in EF?
I am having two date values, one already stored in the database and the other selected by the user using DatePicker. The use case is to search for a particular date from the database.
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Check if key exists and iterate the JSON array using Python
I have a bunch of JSON data from Facebook posts like the one below:
7 Answers
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How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops
...for Pattern Matching.
To use in Excel follow these steps:
Step 1: Add VBA reference to "Microsoft VBScript Regular Expressions 5.5"
Select "Developer" tab (I don't have this tab what do I do?)
Select "Visual Basic" icon from 'Code' ribbon section
In "Microsoft Visual Basic for Applications" wi...
Match whitespace but not newlines
I sometimes want to match whitespace but not newline.
6 Answers
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