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How can I convert a string to a number in Perl?
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This is a simple solution:
Example 1
my $var1 = "123abc";
print $var1 + 0;
Result
123
Example 2
my $var2 = "abc123";
print $var2 + 0;
Result
0
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Ruby, remove last N characters from a string?
...diomatic (and I'd argue, even more readable than other answers here):
'abc123'.delete_suffix('123') # => "abc"
'abc123'.delete_suffix!('123') # => "abc"
It's even significantly faster (almost 40% with the bang method) than the top answer. Here's the result of the same benchmark:
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Removing all non-numeric characters from string in Python
... this is the most efficient way, but:
>>> ''.join(c for c in "abc123def456" if c.isdigit())
'123456'
The ''.join part means to combine all the resulting characters together without any characters in between. Then the rest of it is a list comprehension, where (as you can probably guess) ...
Apply a function to every row of a matrix or a data frame
Suppose I have a n by 2 matrix and a function that takes a 2-vector as one of its arguments. I would like to apply the function to each row of the matrix and get a n-vector. How to do this in R?
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Test whether string is a valid integer
...of "+" (e.g. +30) which obviously is an integer.
Results:
$ int_check.sh 123
123 is an integer !!
$ int_check.sh 123+
ERROR: first parameter must be an integer.
$ int_check.sh -123
-123 is an integer !!
$ int_check.sh +30
+30 is an integer !!
$ int_check.sh -123c
ERROR: first parameter must be...
How can I pad a String in Java?
...*chars
Display '*' for characters of password:
String password = "secret123";
String padded = String.format("%"+password.length()+"s", "").replace(' ', '*');
output has the same length as the password string:
secret123
*********
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Passing data between a fragment and its container activity
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Since you are accessing a function within YOUR Activity (and not the parent Android activity) you will need to cast your getActivity() call: ((MyActivity) getActivity()).getResult();
– Nick
Feb 21 '12 at 17...
Android - implementing startForeground for a service?
...recent versions of Android. This is how i solved it:
Activity:
override fun onCreate(savedInstanceState: Bundle?) {
val intent = Intent(this, BackgroundService::class.java)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
startForegroundService(intent)
} else {
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How to get the data-id attribute?
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To get the contents of the attribute data-id (like in <a data-id="123">link</a>) you have to use
$(this).attr("data-id") // will return the string "123"
or .data() (if you use newer jQuery >= 1.4.3)
$(this).data("id") // will return the number 123
and the part after data- ...
Host 'xxx.xx.xxx.xxx' is not allowed to connect to this MySQL server
...ccess the MySQL Database on your actual server (say your remote address is 123.123.123.123 at port 3306 as user 'root' and I want to change permissions on database 'dataentry'. Remember to change the IP Address, Port, and database name to your settings)
mysql -u root -p
Enter password: <enter p...