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Is there a standard function to check for null, undefined, or blank variables in JavaScript?
...l evaluate to true if value is not:
null
undefined
NaN
empty string ("")
0
false
The above list represents all possible falsy values in ECMA-/Javascript. Find it in the specification at the ToBoolean section.
Furthermore, if you do not know whether a variable exists (that means, if it was decla...
Measuring the distance between two coordinates in PHP
...atitudeFrom, $longitudeFrom, $latitudeTo, $longitudeTo, $earthRadius = 6371000)
{
// convert from degrees to radians
$latFrom = deg2rad($latitudeFrom);
$lonFrom = deg2rad($longitudeFrom);
$latTo = deg2rad($latitudeTo);
$lonTo = deg2rad($longitudeTo);
$latDelta = $latTo - $latFrom;
$lo...
Can you determine if Chrome is in incognito mode via a script?
...
10 Answers
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How do you create a random string that's suitable for a session ID in PostgreSQL?
...ndom_string(length integer) returns text as
$$
declare
chars text[] := '{0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}';
result text := '';
i integer := 0;
begin
if length < 0 then
raise exception 'Given le...
Show DialogFragment with animation growing from a point
...
+100
Being DialogFragment a wrapper for the Dialog class, you should set a theme to your base Dialog to get the animation you want:
publi...
Deleting queues in RabbitMQ
...
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edited Apr 30 at 8:23
Adeel Ansari
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Symbolic links and synced folders in Vagrant
...llh.com/…
– jdunk
Mar 15 '15 at 8:06
5
Running vagrant up in a shell with admin rights is all t...
Fastest way to determine if an integer is between two integers (inclusive) with known sets of values
...e interval to the point of origin and checks if number is in the interval [0, D], where D = upper - lower. If number below lower bound: negative, and if above upper bound: larger than D.
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im...
How do I move the turtle in LOGO? [closed]
...BACK ## [BK] - Move turtle back
BACKGROUND ## [BG] - Set Background color (0-15)
0 - Black
1 - White
2 - Red
3 - Cyan
4 - Purple
5 - Green
6 - Blue
7 - Yellow
8 - Orange
9 - Brown
10 - Light Red
11 - Grey 1
12 - Grey 2
13 - Light Green
14 - Light Blue
15 - Grey 3
CLEARSCREEN [CS] - Clear Scre...
How to semantically add heading to a list
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answered Jan 20 '12 at 0:53
AlohciAlohci
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