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Difference between null and empty (“”) Java String
...:
System.out.println(a.length()); // 0
System.out.println(b.length()); // error; b is not an object
"" is still a string, meaning you can call its methods and get meaningful information. null is an empty variable - there's literally nothing there.
...
微博为什么限制140字(附短信70字限制考) - 创意 - 清泛网 - 专注C/C++及内核技术
...就注册了，之后再也没登录过。今天在人人网转发状态，提示我超过140字了，突然就好奇大家都在凑什么热闹，为什么除了网易微博，都限制140个字呢?
当然也已经有过关于这个问题的解释，比如人民网上这位“并没有twitter方...
Checking for a dirty index or untracked files with Git
.../null| egrep "^(M| M)" | wc -l)
Note: The 2>/dev/null filters out the error messages so you can use these commands on non-git directories. (They'll simply return 0 for the file counts.)
Edit:
Here are the posts:
Adding Git Status Information to your Terminal Prompt
Improved Git-enabled Shel...
How can I get a count of the total number of digits in a number?
...by @AlanSingfield. This fix (adding a cast to double) causes a computation error when the input value is exactly -999999999999999999: the LOG10 method returns 20 instead of 19. The LOG10 method also must have a if guard for the case when the input value is zero.
The LOG10 method is quite tricky to ...
Regex to match only letters
...
with python 3 this yields an error bad escape \p at position 0
– matanster
Apr 19 '19 at 16:23
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PostgreSQL: Modify OWNER on all tables simultaneously in PostgreSQL
...d to a database that I created (i.e. not a system database), it says this: ERROR: cannot reassign ownership of objects owned by role postgres because they are required by the database system
– thnee
Mar 8 '13 at 23:19
...
Removing multiple keys from a dictionary safely
...rches the same. And this might help.
Update
The above code will throw an error if a key does not exist in the dict.
DICTIONARY = {'a': 'valueA', 'b': 'valueB', 'c': 'valueC', 'd': 'valueD'}
keys = ['a', 'l', 'c']
def remove_keys(key):
try:
DICTIONARY.pop(key, None)
except:
...
Eclipse RCP Plug-in开发自学教程（Eclipse3.6） - 文档下载 - 清泛网 - ...
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14 提示和策略 ...................................................................................................................................143
14.1 控制台日志 .......................................................
What is the difference between varchar and nvarchar?
...ead from or write to the database. Conversions take time, and are prone to errors. And recovery from conversion errors is a non-trivial problem.
If you are interfacing with an application that uses only ASCII, I would still recommend using Unicode in the database. The OS and database collation algo...
Multiple working directories with Git?
... the former working tree.
Git 2.13 (Q2 2017) add a lock option in commit 507e6e9 (12 Apr 2017) by Nguyễn Thái Ngọc Duy (pclouds).
Suggested-by: David Taylor (dt).
Helped-by: Jeff King (peff).
(Merged by Junio C Hamano -- gitster -- in commit e311597, 26 Apr 2017)
Allow to lock a worktree imm...