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How to set DOM element as the first child?
I have element E and I'm appending some elements to it. All of a sudden, I find out that the next element should be the first child of E. What's the trick, how to do it? Method unshift doesn't work because E is an object, not array.
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Adding a column to an existing table in a Rails migration
...ontaining line:
add_column :users, email, string
Then do a rake db:migrate and it'll run the new migration, creating the new column.
If you have not yet run the original migration you can just edit it, like you're trying to do. Your migration code is almost perfect: you just need to remove the add_...
How to get “wc -l” to print just the number of lines without file name?
outputs number of lines and file name.
9 Answers
9
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Find Oracle JDBC driver in Maven repository
...;ojdbc14</artifactId>
<version>10.2.0.3.0</version>
...and the URL to download the file which in this case is
http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/index.html.
Once you've downloaded the JAR just add it to your computer repository with (note I pulled the ...
How to use chrome web inspector to view hover code
... hover code for a button? You will have to hover the mouse over the button and thus cannot use it (mouse) in the inspector. Are there any shortcuts or other ways to accomplish this in the inspector?
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Programmatically creating Markdown tables in R with KnitR
I am just starting to learn about KnitR and the use of Markdown in generating R documents and reports. This looks to be perfect for a lot of the day to day reporting that I have to do with my job. However, one thing that I'm not seeing is an easy way to print data frames and tables using Markdown fo...
What does the star operator mean, in a function call?
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s = sum(1, 2)
The double star ** does the same, only using a dictionary and thus named arguments:
values = { 'a': 1, 'b': 2 }
s = sum(**values)
You can also combine:
def sum(a, b, c, d):
return a + b + c + d
values1 = (1, 2)
values2 = { 'c': 10, 'd': 15 }
s = sum(*values1, **values2)
w...
Print all but the first three columns
...$(i-2)=$i; NF=NF-2; print $0}' | tr ' ' '-'
3-4-5-6-7
This is the fixed and parametrized version of larsr solution:
$ echo '1 2 3 4 5 6 7' |
awk '{for(i=n;i<=NF;i++)$(i-(n-1))=$i;NF=NF-(n-1);print $0}' n=4 | tr ' ' '-'
4-5-6-7
All other answers before Sep-2013 are nice but add extra spac...
Why is Double.MIN_VALUE in not negative
... actually the minimum value that Doubles can take? It is a positive value, and a Double can of course be negative.
6 Answer...
How can I inspect disappearing element in a browser?
...element that contains the disappearing element. Right click on the element and apply "Break on... > Subtree Modifications." This will throw a debugger pause before the element disappears, which will allow you to interact with the element in a paused state.
Update Oct 22 2019: with the release of...