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How to check if a string is a valid hex color representation?
..., you can prefix number literals to get a number in other radii.
Here's a table for clarification:
╭─────────────┬────────────┬────────┬───────────────────╮
│ Radix │ Charact...
JavaScript: empty array, [ ] evaluates to true in conditional structures. Why is this?
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there is a handful table showing unexpected situations using == comparator in the link you posted. I commented just to be careful when expecting true or false evaluation.
– m.rufca
Apr 24 '18 at 21:10
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Is it good practice to use java.lang.String.intern()?
...5x less memory than rolling your own object pool
Be sure to tune -XX:StringTableSize (the default is probably too small; set a Prime number)
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How do I create a URL shortener?
...n auto-generated, unique numerical key (the auto-incremented id of a MySQL table for example).
For this example, I will use 12510 (125 with a base of 10).
Now you have to convert 12510 to X62 (base 62).
12510 = 2×621 + 1×620 = [2,1]
This requires the use of integer division and modulo. A pseudo...
Creating an R dataframe row-by-row
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data.table seems to be even faster than pre-allocation using data.frames. Testing here: stackoverflow.com/a/11486400/636656
– Ari B. Friedman
Jul 15 '12 at 2:02
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It is more efficient to use if-return-return or if-else-return?
...most all if-else-return are cases of guard clauses and those are always testable (mock the tested expression) without the else.
– cowbert
Mar 28 '18 at 3:22
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Check if Python Package is installed
...s:
import subprocess
import sys
reqs = subprocess.check_output([sys.executable, '-m', 'pip', 'freeze'])
installed_packages = [r.decode().split('==')[0] for r in reqs.split()]
The result:
print(installed_packages)
[
"Django",
"six",
"requests",
]
Check if requests is installed:
i...
Which Java Collection should I use?
...resenting a Collection with no duplicates.
HashSet: A Set backed by a Hashtable. Fastest and smallest memory usage, when ordering is unimportant.
LinkedHashSet: A HashSet with the addition of a linked list to associate elements in insertion order. The "next" element is the next-most-recently insert...
How to atomically delete keys matching a pattern using Redis
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Lua's unpack transforms a table in a "list of independent variables" (other languages call that explode) but the max number is not dependent on the syste memory; it's fixed in lua through the LUAI_MAXSTACK constant. In Lua 5.1 & LuaJIT it's 8000 a...
What is the purpose of base 64 encoding and why it used in HTTP Basic Authentication?
...- it's an encoding. It's a way of representing binary data using only printable (text) characters.
See this paragraph from the wikipedia page for HTTP Basic Authentication:
While encoding the user name and password with the Base64 algorithm typically makes them unreadable by the naked eye, the...