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Ruby, Difference between exec, system and %x() or Backticks
...You have to provide the command as a string argument to this method. For example:
>> system("date")
Wed Sep 4 22:03:44 CEST 2013
=> true
The invoked program will use the current STDIN, STDOUT and STDERR objects of your Ruby program. In fact, the actual return value is either true, false...
What does Python's eval() do?
... eval function lets a Python program run Python code within itself.
eval example (interactive shell):
>>> x = 1
>>> eval('x + 1')
2
>>> eval('x')
1
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Counting the Number of keywords in a dictionary in python
...ill negligible in comparison to whatever else your program is doing.
d = {x: x**2 for x in range(1000)}
len(d)
# 1000
len(d.keys())
# 1000
%timeit len(d)
# 41.9 ns ± 0.244 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
%timeit len(d.keys())
# 83.3 ns ± 0.41 ns per loop (mean ...
Why doesn't Dictionary have AddRange?
...ut in a manner that fits with the Framework guidelines.
AddRange doesn't exist because a range doesn't have any meaning to an associative container, as the range of data allows for duplicate entries. E.g if you had an IEnumerable<KeyValuePair<K,T>> that collection does not guard against...
Build android release apk on Phonegap 3.x CLI
How can I build an android app locally using the Phonegap 3.x CLI, ready to release? I check the bin folder generated inside the platforms/android directory of the project, and only has .debug APKs.
...
What is an NP-complete in computer science?
...vable in realistic time.
Edit: As others have noted, there are often approximate solutions for NP-Complete problems. In this case, the approximate solution usually gives an approximation bound using special notation which tells us how close the approximation is.
...
Pass Variables by Reference in Javascript
...orld"
You can iterate over the properties of an array with a numeric index and modify each cell of the array, if you want.
var arr = [1, 2, 3];
for (var i = 0; i < arr.length; i++) {
arr[i] = arr[i] + 1;
}
It's important to note that "pass-by-reference" is a very specific term. It doe...
Linq Query keeps throwing “Unable to create a constant value of type System.Object…”, Why?
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Can you please explain the difference between "t.CustID == custIdToQuery" and "t.CustID.Equals(custIdToQuery)". thanks in advance
– Neel
Jan 4 '11 at 10:20
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how to return index of a sorted list? [duplicate]
I need to sort a list and then return a list with the index of the sorted items in the list. For example, if the list I want to sort is [2,3,1,4,5] , I need [2,0,1,3,4] to be returned.
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