大约有 45,000 项符合查询结果（耗时：0.0640秒） [XML]
Returning a boolean from a Bash function
I want to write a bash function that check if a file has certain properties and returns true or false. Then I can use it in my scripts in the "if". But what should I return?
...
How to check if a stored procedure exists before creating it
...edure in PL/SQL.
Update:
Your question title is a little bit confusing.
If you only need to create a procedure if it not exists, then your code is just fine.
Here's what SSMS outputs in the create script:
IF EXISTS ( SELECT *
FROM sys.objects
WHERE object_id = OBJE...
How to print binary tree diagram?
...
I've created simple binary tree printer. You can use and modify it as you want, but it's not optimized anyway. I think that a lot of things can be improved here ;)
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class BTreePrinterTest {
p...
Interview question: Check if one string is a rotation of other string [closed]
...
First make sure s1 and s2 are of the same length. Then check to see if s2 is a substring of s1 concatenated with s1:
algorithm checkRotation(string s1, string s2)
if( len(s1) != len(s2))
return false
if( substring(s2,concat(s1,s1))
return true
return false
end
In Java:
bool...
How to check if an activity is the last one in the activity stack for an application?
I want to know if user would return to the home screen if he exit the current activity.
10 Answers
...
How to check that a string is an int, but not a double, etc.?
...integer beforehand, so that I can give a helpful error message to the user if it's wrong. PHP has is_int() , but that returns false for string like "2" .
...
Best way to compare two complex objects
....
For value types, you can typically just call their Equals method. Even if the fields or properties were never explicitly assigned, they would still have a default value.
For reference types, you should first call ReferenceEquals, which checks for reference equality – this would serve as an ef...
What does `kill -0 $pid` in a shell script do?
...
sending the signal 0 to a given PID just checks if any process with the given PID is running and you have the permission to send a signal to it.
For more information see the following manpages:
kill(1)
$ man 1 kill
...
If sig is 0, then no signal is sent, but error chec...
Convert nullable bool? to bool
...
You ultimately have to decide what the null bool will represent. If null should be false, you can do this:
bool newBool = x.HasValue ? x.Value : false;
Or:
bool newBool = x.HasValue && x.Value;
Or:
bool newBool = x ?? false;
...
What is the equivalent of “none” in django templates?
I want to see if a field/variable is none within a Django template. What is the correct syntax for that?
7 Answers
...