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Finding Variable Type in JavaScript
...ring"
> typeof true
"boolean"
> typeof 42
"number"
So you can do:
if(typeof bar === 'number') {
//whatever
}
Be careful though if you define these primitives with their object wrappers (which you should never do, use literals where ever possible):
> typeof new Boolean(false)
"objec...
Converting newline formatting from Mac to Windows
...
For anyone that comes across this now, the Homebrew formula is now called dos2unix. You'll want to brew install dos2unix.
– Geoff
Apr 26 '16 at 19:06
...
Query EC2 tags from within instance
...
The ec2metadata tool is deprecated. Now you query the 'magic' URL at 169.254.169.254/latest/meta-data - hit it with cURL and it gives you magic endpoints you can use to get various bits of data. In this case curl http://169.254.169.254/latest/meta-data/instance...
How to grep a text file which contains some binary data?
...binary files are treated differently:
When searching binary data, grep now may treat non-text bytes as line
terminators. This can boost performance significantly.
So what happens now is that with binary data, all non-text bytes
(including newlines) are treated as line terminators. If you wan...
Cannot import the keyfile 'blah.pfx' - error 'The keyfile may be password protected'
... key file, any other users that get latest on this checked in key file are now going to experience this bug. If any of those users check in their "fix" and I get latest, then my machine is now broken again... and so on. Microsoft have started a trouble ticket on this and assigned it to the VS2010 ...
How do I change the string representation of a Python class? [duplicate]
...
The closest equivalent to Java's toString is to implement __str__ for your class. Put this in your class definition:
def __str__(self):
return "foo"
You may also want to implement __repr__ to aid in debugging.
See here for more information:
Special Method Names - Basic Cu...
error LNK2019: 无法解析的外部符号_socket，该符号在函数 中被引用 - c++1...
1>NetClient.obj : error LNK2019: 无法解析的外部符号 _closesocket@4，该符号在函数 _main 中被引用
1>NetClient.obj : error LNK2019: 无法解析的外部符号 _inet_ntoa@4，该符号在函数 _main 中被引用
1>NetClient.obj : error LNK2019: 无法解析的外部符...
Access denied for user 'root'@'localhost' while attempting to grant privileges. How do I grant privi
...she does not have,
and the server seem to think something is not here ...
Now, what's missing then ?
On my system, I get this:
mysql> select version();
+------------+
| version() |
+------------+
| 5.5.21-log |
+------------+
1 row in set (0.00 sec)
mysql> SHOW GRANTS FOR 'root'@'localhos...
Calculating distance between two points, using latitude longitude?
... upon this SOF article.
Obviously, the question was asked in 2010 and its now 2019.
But it comes up early in an internet search. The original question does not discount use of third-party-library (when I wrote this answer).
public double calculateDistanceInMeters(double lat1, double long1, double...
check if variable is dataframe
when my function f is called with a variable I want to check if var is a pandas dataframe:
2 Answers
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