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How to check if a variable is set in Bash?
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(Usually) The right way
if [ -z ${var+x} ]; then echo "var is unset"; else echo "var is set to '$var'"; fi
where ${var+x} is a parameter expansion which evaluates to nothing if var is unset, and substitutes the string x otherw...
Accessing Object Memory Address
When you call the object.__repr__() method in Python you get something like this back:
9 Answers
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How does the “final” keyword in Java work? (I can still modify an object.)
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You are always allowed to initialize a final variable. The compiler makes sure that you can do it only once.
Note that calling methods on an object stored in a final variable has nothing to do with the semantics of final. In other words:...
Count immediate child div elements using jQuery
... how the question specifies he wants to count only the "div" elements, not all elements.
– Angel Blanco
Mar 5 '14 at 11:55
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Java 8: How do I work with exception throwing methods in streams?
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You need to wrap your method call into another one, where you do not throw checked exceptions. You can still throw anything that is a subclass of RuntimeException.
A normal wrapping idiom is something like:
private void safeFoo(final A a) {
try {
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Check list of words in another string [duplicate]
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@Ockonal: and if you want to check that all words from that list are inside the string, just replace any() above with all()
– Nas Banov
Jul 17 '10 at 23:23
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Best way to clear a PHP array's values
Which is more efficient for clearing all values in an array? The first one would require me to use that function each time in the loop of the second example.
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Bytecode features not available in the Java language
...case of the invokespecial bytecode is handled for this class. It is set by all modern Java compilers (where "modern" is >= Java 1.1, if I remember correctly) and only ancient Java compilers produced class files where this was un-set. This flag exists only for backwards-compatibility reasons. Note...
Dual emission of constructor symbols
...e Itanium C++ ABI.
According to the ABI, the mangled name for your Thing::foo() is easily parsed:
_Z | N | 5Thing | 3foo | E | v
prefix | nested | `Thing` | `foo`| end nested | parameters: `void`
You can read the constructor names similarly, as below. Notice how the constructor ...
How can I reliably determine the type of a variable that is declared using var at design time?
...pass which analyzes only the "top level" stuff in the source code. We skip all the method bodies. That allows us to quickly build up a database of information about what namespace, types and methods (and constructors, etc) are in the source code of the program. Analyzing every single line of code i...