大约有 46,000 项符合查询结果（耗时：0.0643秒） [XML]
Can I export a variable to the environment from a bash script without sourcing it?
...tioned, is to use source or . to execute the script in the context of the calling shell:
$ cat set-vars1.sh
export FOO=BAR
$ . set-vars1.sh
$ echo $FOO
BAR
Another way is to have the script, rather than setting an environment variable, print commands that will set the environment variable:
$ c...
What's the difference between fill_parent and wrap_content?
... value:
android:layout_width="100dp"
android:layout_height="200dp"
Generally that is not as good, though, because it is not as flexible for different sized devices. After you have understood wrap_content and match_parent, the next thing to learn is layout_weight.
See also
What does android:lay...
Test if a class has an attribute?
...
to only check if the attribute is present, which is usually all that is needed for parameterless/propertyless attributes, it's cheaper to use .IsDefined, as it will query the metadata, and not deserialize and instantiate the attribute object.
– Lasse V. Karl...
Is there a “do … while” loop in Ruby?
...
It looks like the begin-end-while loop is actually evaluating the condition before running the loop. The difference between that and a regular while loop is that it's guaranteed to run at least once. It's just close enough to do...while to cause problems.
...
Reducing MongoDB database file size
...compact command and WiredTiger it looks like the extra disk space will actually be released to the OS.
UPDATE: as of v1.9+ there is a compact command.
This command will perform a compaction "in-line". It will still need some extra space, but not as much.
MongoDB compresses the files by:
cop...
Disable Maven warning message - “Selected war files include a WEB-INF/web.xml which will be ignored”
...if you are happy with the default web.xml then don't write one yourself at all.
– Ustaman Sangat
Oct 17 '12 at 16:07
|
show 1 more comment
...
What is the difference between .map, .every, and .forEach?
I've always wondered what the difference between them were. They all seem to do the same thing...
4 Answers
...
Select objects based on value of variable in object using jq
...t work: termux-contact-list |jq -r '.[] | select(.name=="$1")|.number'. I call it like cool_fn Name1. However, this works: termux-contact-list |jq -r '.[] | select(.name=="Name1")|.number'
– Timo
Aug 18 '18 at 8:13
...
Best practice to validate null and empty collection in Java
...evaluate the right operand. So if m == null, then m.isEmpty() will not be called (not needed, the result is true).
– icza
Jul 29 '16 at 9:05
...
How to check if an object is nullable?
...pe if boxed, but you can with generics:
- so how about below. This is actually testing type T, but using the obj parameter purely for generic type inference (to make it easy to call) - it would work almost identically without the obj param, though.
static bool IsNullable<T>(T obj)
{
if (...