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...员中心 中文社区 关于 var _hmt = _hmt || []; (function() { var hm = document.createElement("script"); hm.src = "https://hm.baidu.com/hm.js?8d287b854d737bdc880e8ddeac1b309d"; var s = document.getElementsByTagName("script")[0]; s.parentNod...
Symbolicating iPhone App Crash Reports
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Also, if used without an address, it allow you to analyse multiple locations by submitting them one by one.
– Paul Ardeleanu
Mar 12 '12 at 10:03
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Fastest way to check if a string matches a regexp in ruby?
...y
require 'benchmark'
str = "aacaabc"
re = Regexp.new('a+b').freeze
N = 4_000_000
Benchmark.bm do |b|
b.report("str.match re\t") { N.times { str.match re } }
b.report("str =~ re\t") { N.times { str =~ re } }
b.report("str[re] \t") { N.times { str[re] } }
b.report("re =~ str...
How does Rails keep track of which migrations have run for a database?
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Rails creates a table in your database called schema_migrations to keep track of which migrations have run.
The table contains a single column, version. When Rails runs a migration, it takes the leading digits in the migration's file name and inserts a row for that "version",...
Checking for an empty field with MySQL
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If you want to find all records that are not NULL, and either empty or have any number of spaces, this will work:
LIKE '%\ '
Make sure that there's a space after the backslash. More info here: http://dev.mysql.com/doc/refman/5.0/en/string-com...
Can enums be subclassed to add new elements?
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If you could tell us more about how you want to use this, we could potentially suggest alternative solutions.
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What does “pending” mean for request in Chrome Developer Window?
... I've seen the same thing in Chrome with the TamperMonkey extension installed.
– sstn
Sep 18 '15 at 12:24
1
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Split string into array of character strings
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This is indeed a regex-expression, called a negative lookahead. Checkout the documentation here: docs.oracle.com/javase/6/docs/api/java/util/regex/…
– Erwin
May 28 '14 at 8:51
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Convert an NSURL to an NSString
...[myURL absoluteString]; But I had met this error and xcode was crashed. -[__NSCFString absoluteString]: unrecognized selector sent to instance 0x791a18e0
– Võ Mai Trinh
Jun 22 '15 at 9:39
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Android file chooser [closed]
...tent in an Intent.createChooser() like this:
private static final int FILE_SELECT_CODE = 0;
private void showFileChooser() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("*/*");
intent.addCategory(Intent.CATEGORY_OPENABLE);
try {
startActivityFor...