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Are JavaScript strings immutable? Do I need a “string builder” in JavaScript?
...s to the same string, modifying one doesn't affect the other
let a = b = "hello";
a = a + " world";
// b is not affected
However, I've always heard what Ash mentioned in his answer (that using Array.join is faster for concatenation) so I wanted to test out the different methods of concatenating s...
Get users by name property using Firebase
...ds.firebaseio.com/users');
var myUser = usersRef.child(escapeEmailAddress('hello@hello.com'))
myUser.set({ email: 'hello@hello.com', name: 'Alex', phone: 12912912 });
Note that since Firebase does not permit certain characters in references (see Creating References), we remove the . and replace i...
Run R script from command line
... add an appropriate #! to the top of the script
#!/usr/bin/env Rscript
sayHello <- function(){
print('hello')
}
sayHello()
I will also note that if you're running on a *unix system there is the useful littler package which provides easy command line piping to R. It may be necessary to use ...
Best Practices: working with long, multiline strings in PHP?
...g. So I might do something like this with your original example:
$text = 'Hello ' . $vars->name . ','
. "\r\n\r\n"
. 'The second line starts two lines below.'
. "\r\n\r\n"
. 'I also don\'t want any spaces before the new line,'
. ' so it\'s butted up against the left...
What does a tilde do when it precedes an expression?
...of presence/absence of a substring in another string in this way
var a = "Hello Baby";
if (a.indexOf("Ba") >= 0) {
// found it
}
if (a.indexOf("Ba") != -1) {
// found it
}
if (a.indexOf("aB") < 0) {
// not found
}
if (a.indexOf( "aB" ) == -1) {
// not found
}
However, i...
Windows recursive grep command-line
...h strings unless the argument is prefixed
with /C. For example, 'FINDSTR "hello there" x.y' searches for "hello" or
"there" in file x.y. 'FINDSTR /C:"hello there" x.y' searches for
"hello there" in file x.y.
Regular expression quick reference:
. Wildcard: any character
* Repeat:...
Remove all child elements of a DOM node in JavaScript
..."height: 100px; width: 100px; border: 1px solid black;">
<span>Hello</span>
</div>
<button id='doFoo'>Remove via innerHTML</button>
Option 1 B: Clearing textContent
As above, but use .textContent. According to MDN this will be faster than innerHTML as b...
How can I count the number of matches for a regex?
...
class Test {
public static void main(String[] args) {
String hello = "HelloxxxHelloxxxHello";
Pattern pattern = Pattern.compile("Hello");
Matcher matcher = pattern.matcher(hello);
int count = 0;
while (matcher.find())
count++;
Syste...
Is there a WebSocket client implemented for Python? [closed]
...on
ws = create_connection("ws://localhost:8080/websocket")
print "Sending 'Hello, World'..."
ws.send("Hello, World")
print "Sent"
print "Receiving..."
result = ws.recv()
print "Received '%s'" % result
ws.close()
Sample server code:
#!/usr/bin/python
import websocket
import thread
import time
de...
Bash history without line numbers
...ing awk to display the contents of a file with $0
$ awk '{print $0}' /tmp/hello-world.txt
Hello World!
[Ex] Using awk to display the contents of a file without explicit $0
$ awk '{print}' /tmp/hello-world.txt
Hello World!
[Ex] Using awk when the history line spans multiple lines
$ history
...