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How to make an Android Spinner with initial text “Select One”?
...lly (when the user has not made a selection yet) displays the text "Select One". When the user clicks the spinner, the list of items is displayed and the user selects one of the options. After the user has made a selection, the selected item is displayed in the Spinner instead of "Select One".
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Is there a performance difference between a for loop and a for-each loop?
...ng strings.get(i) */ }
Second, the preferred way since it's less error prone (how many times have YOU done the "oops, mixed the variables i and j in these loops within loops" thing?).
for (String s : strings) { /* do something using s */ }
Third, the micro-optimized for loop:
int size = string...
Markdown: continue numbered list
...bered block. If you leave 2 blank lines, it restarts numbering; leave only one and it continues.
– Rhubarb
Aug 21 '19 at 10:28
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Programmer Puzzle: Encoding a chess board state throughout a game
...ion of pieces on the board. Encoding simply the positions of the pieces is one thing but the problem says “all subsequent legal moves”. The problem also says nothing about knowing the moves up to this point. That’s actually a problem as I’ll explain.
Castling
The game has proceeded as foll...
Catch multiple exceptions in one line (except block)
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How do I catch multiple exceptions in one line (except block)
Do this:
try:
may_raise_specific_errors():
except (SpecificErrorOne, SpecificErrorTwo) as error:
handle(error) # might log or have some other default behavior...
The parentheses are requir...
Stash only one file out of multiple files that have changed with Git?
How can I stash only one of multiple changed files on my branch?
33 Answers
33
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Only one expression can be specified in the select list when the subquery is not introduced with EXI
...lumn is it supposed to compare A_ID to? Your subquery must only return the one column needed for the comparison to the column on the other side of the IN. So the query needs to be of the form:
SELECT * From ThisTable WHERE ThisColumn IN (SELECT ThatColumn FROM ThatTable)
You also want to add sort...
Remove multiple whitespaces
... are using \s\s+ which means whitespace(space, tab or newline) followed by one or more whitespace. Which effectively means replace two or more whitespace with a single space.
What you want is replace one or more whitespace with single whitespace, so you can use the pattern \s\s* or \s+ (recommend...
Difference between mkdir() and mkdirs() in java for java.io.File [closed]
Can anyone tell me the difference between these two methods:
3 Answers
3
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Database development mistakes made by application developers [closed]
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1. Not using appropriate indices
This is a relatively easy one but still it happens all the time. Foreign keys should have indexes on them. If you're using a field in a WHERE you should (probably) have an index on it. Such indexes should often cover multiple columns based on the q...