Symbols are like strings but they are immutable – they can’t be modified. They are only put into memory once, making them very efficient to use for things like keys in hashes but they stay in memory until the program exits. This makes them a memory hog if you misuse them. If you dynamically create … Read more
I Changed my project settings to not include the dSYM file while building: Changing it to include the dSYM File helped the profiler desymbolize the symbols and fixed my issue:
Symbols are used where you have a closed set of identifiers that you want to be able to compare quickly. When you have two String instances they are not guaranteed to be interned[1], so to compare them you must often check their contents by comparing lengths and even checking character-by-character whether they are the same. … Read more
Try using the HashWithIndifferentAccess like APP_CONFIG = HashWithIndifferentAccess.new(YAML.load(File.read(File.expand_path(‘../app.yml’, __FILE__))))
The main difference is that multiple symbols representing a single value are identical whereas this is not true with strings. For example: irb(main):007:0> :test.object_id => 83618 irb(main):008:0> :test.object_id => 83618 irb(main):009:0> :test.object_id => 83618 Those are three references to the symbol :test, which are all the same object. irb(main):010:0> “test”.object_id => -605770378 irb(main):011:0> “test”.object_id => … Read more
The @ symbol denotes a Java Annotation. What a Java annotation does, is that it adds a special attribute to the variable, method, class, interface, or other language elements. (This can be configured when you declare the annotation) When you add an annotation to something, other parts of the program can check whether something has … Read more
You can use \D which means non digits. var removedText = self.val().replace(/\D+/g, ”); jsFiddle. You could also use the HTML5 number input. <input type=”number” name=”digit” /> jsFiddle.
No, python doesn’t have a symbol type. However string literals are interned by default and other strings can be interned using the intern function. So using string literals as keys in dictionaries is not less performant than using symbols in ruby.
Try using symbol-name: (symbol-name ‘some-symbol)
Consider this: x = :sym y = :sym (x.__id__ == y.__id__ ) && ( :sym.__id__ == x.__id__) # => true x = “string” y = “string” (x.__id__ == y.__id__ ) || ( “string”.__id__ == x.__id__) # => false So, however you create a symbol object, as long as its contents are the same, it will … Read more