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Best implementation for hashCode method for a collection
...he field f is a boolean:
calculate (f ? 0 : 1);
If the field f is a byte, char, short or int: calculate (int)f;
If the field f is a long: calculate (int)(f ^ (f >>> 32));
If the field f is a float: calculate Float.floatToIntBits(f);
If the field f is a double: calculate Double.doubleToLong...
Calculate difference between two datetimes in MySQL
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USE TIMESTAMPDIFF MySQL function. For example, you can use:
SELECT TIMESTAMPDIFF(SECOND, '2012-06-06 13:13:55', '2012-06-06 15:20:18')
In your case, the third parameter of TIMSTAMPDIFF function would be the current login time (NOW()). Second parameter would be the last login time, w...
Select datatype of the field in postgres
...tion_schema (8.4 docs referenced here, but this is not a new feature):
=# select column_name, data_type from information_schema.columns
-# where table_name = 'config';
column_name | data_type
--------------------+-----------
id | integer
default_printer_id | integer
mast...
Simpler way to put PDB breakpoints in Python code?
...t you'll have to record your own (rather than copy/paste above) as special chars are involved (for escape etc).
– arcseldon
Feb 18 '19 at 6:54
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Jquery select all elements that have $jquery.data()
Select elements that i have previously set with jquery.data();
7 Answers
7
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jQuery to serialize only elements within a div
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Wouldn't $("#divId").find("select, textarea, input").serialize(); yeild better performance? I imagine the above could get slow if the div had lots of elements, like a table with several rows/columns.
– David Murdoch
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- how to allow only one item selected?
I have a <SELECT multiple> field with multiple options and I want to allow it to have only one option selected at the same time but user can hold CTRL key and select more items at once.
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Eclipse: How do you change the highlight color of the currently selected method/expression?
...from the Annotation types list.
Then, be sure that Text as highlighted is selected, then choose the desired color.
And, a picture is worth a thousand words...
(source: coobird.net)
(source: coobird.net)
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Splitting on first occurrence
...in the list will contain the remainder of the string (inclusive of any sep chars/strings).
– BuvinJ
Sep 10 '19 at 13:01
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Drop data frame columns by name
...op=FALSE to keep R from converting your data frame to a vector if you only select a single column. Don't forget that data frames are lists, so list selection (one-dimensional like I did) works perfectly well and always returns a list. Or a data frame in this case, which is why I prefer to use it.
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