How do I split a string in Java?

I want to split the string `"004-034556"` into two strings by the delimiter `"-"`: ``` part1 = "004"; part2 = "034556"; ``` That means the first string will contain the characters before `'-'`, and t...

24 Jul at 23:41

How do I check if a list is empty?

For example, if passed the following: ``` a = [] ``` How do I check to see if `a` is empty?

18 Nov at 11:13

Convert string "Jun 1 2005 1:33PM" into datetime

How do I convert the following string to a [datetime]( object? ``` "Jun 1 2005 1:33PM" ```

7 Aug at 23:6

How do I compare strings in Java?

I've been using the `==` operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into `.equals()` instead, and it fixed the bug. Is `==` bad? When shou...

23 Jan at 13:36

How can I validate an email address in JavaScript?

I'd like to check if the user input is an email address in JavaScript, before sending it to a server or attempting to send an email to it, to prevent the most basic mistyping. How could I achieve this...

Find the current directory and file's directory

How do I determine: 1. the current directory (where I was in the shell when I ran the Python script), and 2. where the Python file I am executing is?

21 Nov at 14:25

How do I perform an IF...THEN in an SQL SELECT?

How do I perform an `IF...THEN` in an `SQL SELECT` statement? For example: ``` SELECT IF(Obsolete = 'N' OR InStock = 'Y' ? 1 : 0) AS Saleable, * FROM Product ```

26 Mar at 06:9

How do I replace all occurrences of a string in JavaScript?

Given a string: ``` s = "Test abc test test abc test test test abc test test abc"; ``` This seems to only remove the first occurrence of `abc` in the string above: ``` s = s.replace('abc', ''); ``` ...

24 Jul at 23:55

What does if __name__ == "__main__": do?

What does this do, and why should one include the `if` statement? ``` if __name__ == "__main__": print("Hello, World!") ``` --- [Why is Python running my module when I import it, and how do I ...

How do I execute a program or call a system command?

How do I call an external command within Python as if I had typed it in a shell or command prompt?

How do I delete a commit from a branch?

How do I delete a commit from my branch history? Should I use `git reset --hard HEAD`?

8 Jul at 04:44

How do I vertically center text with CSS?

I have a `<div>` element which contains text and I want to align the contents of this `<div>` vertically center. Here is my `<div>` style: ``` #box { height: 170px; width: 270px; background: #00...

16 Sep at 07:13

`git fetch` a remote branch

The remote repository contains various branches such as `origin/daves_branch`: ``` $ git branch -r origin/HEAD -> origin/master origin/daves_branch origin/master ``` How do I switch to `daves_branch`...

19 Feb at 18:25

How do I get the current time?

How do I get the current time?

1 Apr at 11:27

How to round to at most 2 decimal places, if necessary

I'd like to round at most two decimal places, but . Input: ``` 10 1.7777777 9.1 ``` Output: ``` 10 1.78 9.1 ``` How can I do this in JavaScript?

5 May at 15:28

How do I test for an empty JavaScript object?

After an AJAX request, sometimes my application may return an empty object, like: ``` var a = {}; ``` How can I check whether that's the case?

17 Jan at 13:22

How do I POST JSON data with cURL?

I use Ubuntu and installed [cURL]( on it. I want to test my Spring REST application with cURL. I wrote my POST code at the Java side. However, I want to test it with...

Message 'src refspec master does not match any' when pushing commits in Git

I clone my repository with: ``` git clone ssh://xxxxx/xx.git ``` But after I change some files and `add` and `commit` them, I want to push them to the server: ``` git add xxx.php git commit -m "TE...

How do I get a timestamp in JavaScript?

I want a single number that represents the current date and time, like a [Unix timestamp](

What is a NullPointerException, and how do I fix it?

What are Null Pointer Exceptions (`java.lang.NullPointerException`) and what causes them? What methods/tools can be used to determine the cause so that you stop the exception from causing the program...

26 May at 16:15

Using global variables in a function

How do I create or use a global variable inside a function? How do I use a global variable that was defined in one function inside other functions? --- `global``UnboundLocalError`[UnboundLocalError...

9 Sep at 14:53

How do I make a flat list out of a list of lists?

I have a list of lists like `[[1, 2, 3], [4, 5, 6], [7], [8, 9]]`. How can I flatten it to get `[1, 2, 3, 4, 5, 6, 7, 8, 9]`? --- [python list comprehensions; compressing a list of lists?](https://...

Get the full URL in PHP

I use this code to get the full URL: ``` $actual_link = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF']; ``` The problem is that I use some masks in my `.htaccess`, so what we see in the URL i...

2 Feb at 09:48

Accessing the index in 'for' loops

How do I access the index while iterating over a sequence with a `for` loop? ``` xs = [8, 23, 45] for x in xs: print("item #{} = {}".format(index, x)) ``` Desired output: ``` item #1 = 8 item #2...

8 Aug at 00:51

How do I get the row count of a Pandas DataFrame?

How do I get the number of rows of a pandas dataframe `df`?

28 Mar at 11:49