大约有 44,000 项符合查询结果（耗时：0.0545秒） [XML]
Check if a string is null or empty in XSLT
How can I check if a value is null or empty with XSL ?
14 Answers
14
...
How to check whether an array is empty using PHP?
...comma separated list (or a single value). What is the easiest way to check if it's empty? I'm assuming I can do so as soon as I fetch the $gameresult array into $gamerow ? In this case it would probably be more efficient to skip exploding the $playerlist if it's empty, but for the sake of argum...
Meaning of “[: too many arguments” error from if [] (square brackets)
...
If your $VARIABLE is a string containing spaces or other special characters, and single square brackets are used (which is a shortcut for the test command), then the string may be split out into multiple words. Each of these ...
Is there any significant difference between using if/else and switch-case in C#?
What is the benefit/downside to using a switch statement vs. an if/else in C#. I can't imagine there being that big of a difference, other than maybe the look of your code.
...
Is it a bad practice to use an if-statement without curly braces? [closed]
...
The problem with the first version is that if you go back and add a second statement to the if or else clauses without remembering to add the curly braces, your code will break in unexpected and amusing ways.
Maintainability-wise, it's always smarter to use the secon...
Simple way to find if two different lists contain exactly the same elements?
What is the simplest way to find if two Lists contain exactly the same elements, in the standard Java libraries?
16 Answer...
How can I check if a directory exists in a Bash shell script?
What command can be used to check if a directory exists or not, within a Bash shell script?
35 Answers
...
How do I check if an index exists on a table field in MySQL?
...me instead of Key_name, this way you don't need to find out the index name if it is automatically added without name.
– Programista
Apr 9 '14 at 11:05
...
Detect the specific iPhone/iPod touch model [duplicate]
...a multiplayer on an iPod 1st gen and iPhone 2G I need to check for the specific device model.
6 Answers
...
How to check for null in Twig?
... on what exactly you need:
is null checks whether the value is null:
{% if var is null %}
{# do something #}
{% endif %}
is defined checks whether the variable is defined:
{% if var is not defined %}
{# do something #}
{% endif %}
Additionally the is sameas test, which does a type st...