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Build vs new in Rails 3
In the Rails 3 docs , the build method for associations is described as being the same as the new method, but with the automatic assignment of the foreign key. Straight from the docs:
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How can I multiply and divide using only bit shifting and adding?
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answered May 5 '10 at 22:31
Andrew ToulouseAndrew Toulouse
1,09311 gold badge99 silver badges1010 bronze badges
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What does |= (ior) do in Python?
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53
|= performs an in-place+ operation between pairs of objects. In particular, between:
sets: a u...
What is the use of the ArraySegment class?
...2, 4 };
array.Dump();
var segment = new ArraySegment<byte>(array, 2, 3);
segment.Dump(); // output: 9, 20, 70
segment.Reverse().Dump(); // output 70, 20, 9
segment.Any(s => s == 99).Dump(); // output false
segment.First().Dump(); // output 9
array.Dump(); // no change
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Python element-wise tuple operations like sum
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138
import operator
tuple(map(operator.add, a, b))
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How to split a delimited string into an array in awk?
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Have you tried:
echo "12|23|11" | awk '{split($0,a,"|"); print a[3],a[2],a[1]}'
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How to return multiple lines JSX in another return statement in React?
... the tags as function calls (see docs). Then the first one becomes:
{[1,2,3].map(function (n) {
return React.DOM.p(...);
})}
And the second one:
{[1,2,3].map(function (n) {
return (
React.DOM.h3(...)
React.DOM.p(...)
)
})}
It should now be clear that the second snippet doesn't re...
Accessing an SQLite Database in Swift
...QLite C calls. If using Xcode 9 or later, you can simply do:
import SQLite3
Create/open database.
let fileURL = try! FileManager.default
.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
.appendingPathComponent("test.sqlite")
// open database...
ANTLR: Is there a simple example?
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453
Note: this answer is for ANTLR3! If you're looking for an ANTLR4 example, then this Q&A demo...
sed: print only matching group
...eplaced with the contents of the group
echo "foo bar <foo> bla 1 2 3.4" |
sed -n 's/.*\([0-9][0-9]*[\ \t][0-9.]*[ \t]*$\)/\1/p'
2 3.4
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