There is a plain-text database of information about every Unicode character available from the Unicode Consortium; the format is described in Unicode Annex #44. The primary information is contained in UnicodeData.txt. Open and close punctuation characters are denoted with Ps (punctuation start) and Pe (punctuation end) in the General_Category field (the third field, delimited by … Read more
In dot notation, the name after the dot is the name of the property being referenced. So: var foo = “bar”; var obj = { foo: 1, bar: 2 }; console.log(obj.foo) // = 1, since the “foo” property of obj is 1, // independent of the variable foo However, in square-bracket notation, the name of … Read more
Following [] is supported in PHP >= 5.4: [‘name’ => ‘test’, ‘id’ => ‘theID’] This is a short syntax only and in PHP < 5.4 it won’t work.
RFC 3986 states A host identified by an Internet Protocol literal address, version 6 [RFC3513] or later, is distinguished by enclosing the IP literal within square brackets (“[” and “]”). This is the only place where square bracket characters are allowed in the URI syntax. So you should not be seeing such URI’s in the … Read more
In a character class (square brackets) any character except ^, -, ] or \ is a literal. This website is a brilliant reference and has lots of info on the nuances of different regex flavours. http://www.regular-expressions.info/refcharclass.html
Yes. 6.5.2.1 paragraph 1 (C99 standard) describes the arguments to the [] operator: One of the expressions shall have type “pointer to object type“, the other expression shall have integer type, and the result has type “type“. 6.5.2.1 paragraph 2 (emphasis added): A postfix expression followed by an expression in square brackets [] is a … Read more
The square brackets are a synonym for the test command. An if statement checks the exit status of a command in order to decide which branch to take. grep -q “$text” is a command, but “$name” = ‘Bob’ is not–it’s just an expression. test is a command, which takes an expression and evaluates it: if … Read more