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On Duplicate Key Update same as insert
I've searched around but didn't find if it's possible.
8 Answers
8
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What's the difference between [ and [[ in Bash? [duplicate]
...to the [ command. It has several enhancements that make it a better choice if you write scripts that target bash. My favorites are:
It is a syntactical feature of the shell, so it has some special behavior that [ doesn't have. You no longer have to quote variables like mad because [[ handles empty...
Find a pair of elements from an array whose sum equals a given number
... its index.
hash(arr[i]) = i
end-for
for i=0 to arr.length - 1 do
# if K-th element exists and it's different then we found a pair
if hash(K - arr[i]) != i
print "pair i , hash(K - arr[i]) has sum K"
end-if
end-for
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How to find all occurrences of an element in a list?
...can use a list comprehension:
indices = [i for i, x in enumerate(my_list) if x == "whatever"]
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How can I convert a zero-terminated byte array to string?
... read. You should save that number and then use it to create your string. If n is the number of bytes read, your code would look like this:
s := string(byteArray[:n])
To convert the full string, this can be used:
s := string(byteArray[:len(byteArray)])
This is equivalent to:
s := string(byteArray...
How do I remove objects from a JavaScript associative array?
...ie. an array with a missing index).
When working with instances of Array, if you do not want to create a sparsely populated array - and you usually don't - then you should use Array#splice or Array#pop.
Note that the delete operator in JavaScript does not directly free memory. Its purpose is to re...
How to do ssh with a timeout in a script?
...g via password-less SSH on a remote host. I want to set a timeout, so that if the remote host is taking an infinite time to run, I want to come out of that ssh session and continue other lines in my sh script.
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What is the difference between the add and offer methods in a Queue in Java?
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I guess the difference is in the contract, that when element can not be added to collection the add method throws an exception and offer doesn't.
From: http://java.sun.com/j2se/1.5.0/docs/api/java/util/Collection.html#add%28E%29
If a...
Is there a way to check if int is legal enum in C#?
...
Check out Enum.IsDefined
Usage:
if(Enum.IsDefined(typeof(MyEnum), value))
MyEnum a = (MyEnum)value;
This is the example from that page:
using System;
[Flags] public enum PetType
{
None = 0, Dog = 1, Cat = 2, Rodent = 4, Bird = 8, Reptile = 16...
Validate a username and password against Active Directory?
...e a username and password against Active Directory? I simply want to check if a username and password are correct.
13 Answe...