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Swift - How to convert String to Double
I'm trying to write a BMI program in swift language.
And I got this problem: how to convert a String to a Double?
29 Answer...
Getting the location from an IP address [duplicate]
I want to retrieve information like the city, state, and country of a visitor from their IP address, so that I can customize my web page according to their location. Is there a good and reliable way to do this in PHP? I am using JavaScript for client-side scripting, PHP for server-side scripting, an...
How to perform case-insensitive sorting in JavaScript?
...have an array of strings I need to sort in JavaScript, but in a case-insensitive way. How to perform this?
15 Answers
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Appending a line to a file only if it does not already exist
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Just keep it simple :)
grep + echo should suffice:
grep -qxF 'include "/configs/projectname.conf"' foo.bar || echo 'include "/configs/projectname.conf"' >> foo.bar
-q be quiet
-x match the whole line
-F pattern is a plain st...
What is the dual table in Oracle?
I've heard people referring to this table and was not sure what it was about.
14 Answers
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Correct Bash and shell script variable capitalization
I run across many shell scripts with variables in all caps, and I've always thought that there is a severe misunderstanding with that. My understanding is that, by convention (and perhaps by necessity long ago), environment variables are in all-caps.
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What's the difference between utf8_general_ci and utf8_unicode_ci?
...tation from early MySQL versions which remains only for backward compatibility. The fixed version was given the name utf8mb4.
Note: Newer versions of MySQL have updated Unicode sorting rules, available under names such as utf8mb4_0900_ai_ci for equivalent rules based on Unicode 9.0 - and with no equ...
How can I create a keystore?
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To answer the question in the title, you create a keystore with the Java Keytool utility that comes with any standard JDK distribution and can be located at %JAVA_HOME%\bin. On Windows this would usually be C:\Program Files\Java\jre7\bin.
So on Windows, op...
How to remove a key from Hash and get the remaining hash in Ruby/Rails?
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Rails has an except/except! method that returns the hash with those keys removed. If you're already using Rails, there's no sense in creating your own version of this.
class Hash
# Returns a hash that includes everything but the given keys.
# hash = { a: true, b: false, c: n...
Difference between TCP and UDP?
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TCP is a connection oriented stream over an IP network. It guarantees that all sent packets will reach the destination in the correct order. This imply the use of acknowledgement packets sent back to the sender, and automatic retransmission, causing additional delays and a general...