大约有 7,000 项符合查询结果（耗时：0.0319秒） [XML]
How do I check if a variable exists in a list in BASH
...iginal string with a space and check against a regex with [[ ]]
haystack='foo bar'
needle='bar'
if [[ " $haystack " =~ .*\ $needle\ .* ]]; then
...
fi
this will not be false positive on values with values containing the needle as a substring, e.g. with a haystack foo barbaz.
(The concept is...
Add an element to an array in Swift
...he way Apple implemented this is kind of irritating. Presumably, anArray+="Foo" does the same thing as anArray+=["Foo"] Personally, I'll only be using the latter syntax to avoid confusing myself.
– original_username
Jul 7 '14 at 5:56
...
What's the difference between String(value) vs value.toString()
...the object passed, for example:
var o = { toString: function () { return "foo"; } };
String(o); // "foo"
On the other hand, if an identifier refers to null or undefined, you can't use the toString method, it will give you a TypeError exception:
var value = null;
String(null); // "null"
value...
How can I start an interactive console for Perl?
...:
> gmtime(2**30)
gmtime(2**30) = Sat Jan 10 13:37:04 2004
> $x = 'foo'
$x = 'foo' = foo
> $x =~ s/o/a/g
$x =~ s/o/a/g = 2
> $x
$x = faa
share
|
improve this answer
|
...
How to use a variable inside a regular expression?
...
How to write quantifiers in f-strings: fr"foo{{1,5}}" (double the braces)
– PunchyRascal
Mar 19 at 18:28
...
Android preferences onclick event
...on="android.intent.action.MAIN"
android:targetPackage="com.example.foo"
android:targetClass="com.example.foo.SomeActivity"
/>
</PreferenceScreen>
you can also use "android:mimetype" to set the mimetype.
...
`from … import` vs `import .` [duplicate]
...the other won't. Here is an example: say we have the following structure:
foo.py
mylib\
a.py
b.py
Now, I want to import b.py into a.py. And I want to import a.py to foo. How do I do this? Two statements, in a I write:
import b
In foo.py I write:
import mylib.a
Well, this will gener...
Get the latest record from mongodb collection
...
This is how to get the last record from all MongoDB documents from the "foo" collection.(change foo,x,y.. etc.)
db.foo.aggregate([{$sort:{ x : 1, date : 1 } },{$group: { _id: "$x" ,y: {$last:"$y"},yz: {$last:"$yz"},date: { $last : "$date" }}} ],{ allowDiskUse:true })
you can add or remove f...
How do I access properties of a javascript object if I don't know the names?
...ect.keys and Array#forEach which makes this a little easier:
var data = { foo: 'bar', baz: 'quux' };
Object.keys(data); // ['foo', 'baz']
Object.keys(data).map(function(key){ return data[key] }) // ['bar', 'quux']
Object.keys(data).forEach(function (key) {
// do something with data[key]
});
ES...
Appending the same string to a list of strings in Python
...ng of "s". like so list2 = ["mystring" + s for s in mylist] = list2 = ['barfoo', 'barfob', 'barfaz', 'barfunk']
– Paul Tuckett
May 14 '19 at 20:53
1
...