大约有 40,000 项符合查询结果（耗时：0.0519秒） [XML]
PHP: exceptions vs errors?
...
Exceptions are thrown - they are intended to be caught. Errors are generally unrecoverable. Lets say for instance - you have a block of code that will insert a row into a database. It is possible that this call fails (duplicate ID) - you will want to have a "Error" which in this case is an "Exc...
Why are unnamed namespaces used and what are their benefits?
...ng directive already took place.
This means you can have free functions called (for example) help that can exist in multiple translation units, and they won't clash at link time. The effect is almost identical to using the static keyword used in C which you can put in in the declaration of identif...
Get value from SimpleXMLElement Object
... i can't believe this is so complicated. why would they make a class called "getName" but not "getValue"? why would they print empty string if you printed it instead of converted it manually to (string). WHY??
– user151496
Oct 17 '16 at 12:31
...
When do we need curly braces around shell variables?
...xpand the variable identified by foobar.
Curly braces are also unconditionally required when:
expanding array elements, as in ${array[42]}
using parameter expansion operations, as in ${filename%.*} (remove extension)
expanding positional parameters beyond 9: "$8 $9 ${10} ${11}"
Doing this every...
Simplest way to detect a mobile device in PHP
...
@kavior.com Yes it can be faked, but we should allow people to fake if they wish... because that would be their intention, why stop people from doing what they specifically want (i.e. load the desktop version for some reason in particular)?
– Nick St...
Rspec doesn't see my model Class. uninitialized constant error
...
Your spec_helper file is missing some important commands. Specifically, it's not including config/environment and initializing rspec-rails.
You can add the following lines to the start of your spec/spec_helper.rb file
ENV["RAILS_ENV"] ||= 'test'
require File.expand_path("../../config/envi...
Principles for Modeling CouchDB Documents
...or instance). Managing the relationships or connections between various, smaller documents can be confusing at first, but CouchDB provides several options for combining disparate pieces into single responses.
The first big one is view collation. When you emit key/value pairs into the results of a m...
Abort makefile if variable not set
... an auxiliary function for that:
# Check that given variables are set and all have non-empty values,
# die with an error otherwise.
#
# Params:
# 1. Variable name(s) to test.
# 2. (optional) Error message to print.
check_defined = \
$(strip $(foreach 1,$1, \
$(call __check_defined,$...
Why does C++11 not support designated initializer lists as C99? [closed]
... named function arguments. But as of right now, name arguments don't officially exist. See N4172 Named arguments for a proposal of this. It would make code less error prone and easier to read.
– David Baird
Nov 29 '15 at 15:11
...
Overriding superclass property with different type in Swift
...
Swift does not allow you to change the class type of any variables or properties. Instead you can create an extra variable in the subclass that handles the new class type:
class Chassis {}
class RacingChassis : Chassis {}
class Car {
...