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Boolean literals in PowerShell
...ts are true, for example. null, empty strings, empty arrays and the number 0 are false.
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How to use arguments from previous command?
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By the way, you could have put the echo on the line by selecting argument 0:
Press Alt-0 Alt-Ctrl-y
Edit:
To answer the question you added to your original:
You can press Alt-0 then repeatedly press Alt-. to step through the previous commands (arg 0). Similarly Alt-- then repeating Alt-. would ...
How do I make a transparent canvas in html5?
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edited Apr 16 '14 at 1:20
Lee Taylor
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What killed my process and why?
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answered Apr 7 '09 at 17:23
dwcdwc
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List comprehension vs map
... map when using exactly the same function:
$ python -mtimeit -s'xs=range(10)' 'map(hex, xs)'
100000 loops, best of 3: 4.86 usec per loop
$ python -mtimeit -s'xs=range(10)' '[hex(x) for x in xs]'
100000 loops, best of 3: 5.58 usec per loop
An example of how performance comparison gets completely r...
Java regular expression OR operator
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edited Jan 9 '10 at 0:57
answered Jan 9 '10 at 0:46
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initialize a vector to zeros C++/C++11
...eed initialization lists for that:
std::vector<int> vector1(length, 0);
std::vector<double> vector2(length, 0.0);
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What is the Scala annotation to ensure a tail recursive function is optimized?
...ps and tricks):
C:\Prog\Scala\tests>scala
Welcome to Scala version 2.8.0.RC5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_18).
Type in expressions to have them evaluated.
Type :help for more information.
scala> import scala.annotation.tailrec
import scala.annotation.tailrec
scala> clas...
How do you validate a URL with a regular expression in Python?
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answered May 6 '09 at 1:09
S.LottS.Lott
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parseInt vs unary plus, when to use which?
..., here are a few differences I know of:
An empty string "" evaluates to a 0, while parseInt evaluates it to NaN. IMO, a blank string should be a NaN.
+'' === 0; //true
isNaN(parseInt('',10)); //true
The unary + acts more like parseFloat since it also accepts decimals.
parseInt on...