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Can I set variables to undefined or pass undefined as an argument?
...tion statement lists, the unpassed arguments are set to undefined. You can test for that with eg.:
function dosomething(arg1, arg2) {
if (arg2===undefined)
arg2= DEFAULT_VALUE_FOR_ARG2;
...
}
With this method you can't tell the difference between dosomething(1) and dosomething(1, unde...
Automatically start forever (node) on system restart
...s easy to use.
How to
To start editing run the following replacing the "testuser" with your desired runtime user for the node process. If you choose a different user other than yourself, you will have to run this with sudo.
$ crontab -u testuser -e
If you have never done this before, it will a...
access denied for load data infile in MySQL
...cribed by Yamir in his post I couldn't make it work.
The file was in /tmp/test.csv with 777 permissions. The MySQL user had file permissions, LOCAL option was not allowed by my MySQL version, so I was stuck.
Finally I was able to solve the problem by running:
sudo chown mysql:mysql /tmp/test.csv
...
MySQL: Insert record if not exists in table
...
I doesn't test in Oracle database. It is working fine at MySQL and tested.
– Mahbub Tito
Oct 16 '16 at 4:15
9
...
C# difference between == and Equals()
...lowing code illustrates the subtle differences in behaviors:
string s1 = "test";
string s2 = "test";
string s3 = "test1".Substring(0, 4);
object s4 = s3;
Console.WriteLine("{0} {1} {2}", object.ReferenceEquals(s1, s2), s1 == s2, s1.Equals(s2));
Console.WriteLine("{0} {1} {2}", object.ReferenceEqual...
RuntimeWarning: DateTimeField received a naive datetime
...
You can also override settings, particularly useful in tests:
from django.test import override_settings
with override_settings(USE_TZ=False):
# Insert your code that causes the warning here
pass
This will prevent you from seeing the warning, at the same time anything ...
How do I create a new line in Javascript?
...ML tag for a newline:
document.write("<br>");
The string Hello\n\nTest in your source will look like this:
Hello!
Test
The string Hello<br><br>Test will look like this in HTML source:
Hello<br><br>Test
The HTML one will render as line breaks for the person vie...
Interfaces — What's the point?
...o that your front end would be written once and (here's the important bit) tested, and you can then plug in further back end items as required:
interface ICreature
{
void Walk(int distance)
}
public class Troll : ICreature
public class Orc : ICreature
//etc
Front end is then:
void SpawnCr...
Convert PDF to image with high resolution
... \
-verbose \
-density 150 \
-trim \
test.pdf \
-quality 100 \
-flatten \
-sharpen 0x1.0 \
24-18.jpg
It results in the left image. Compare this to the result of my original command (the image on the right):
(To really see and a...
Android App Not Install. An existing package by the same name with a conflicting signature is alread
...have an application in LIVE in playstore, now I kept installed that app in testing device and now For updating newer version of app I'm updating "versionno" and "versionname" in app build.gradle file. Now I have made an release build with signed key, now while im trying to install that build in it ...