brackets

This question already has an answer here : Where can I get info on the object parameter syntax for JavaScript functions? (1 answer) Closed 3 years ago . I was reading some tweets and I came across this tweet by Dan Abromov The syntax has me confused. const Font = ({ children }) => <Block... What is the point of { } around children? Clearly its not an object. I presume its ES2015 feature. Many thanks It's a destructuring binding pattern. It indicates that the parameter children should be bound to the value of the children property of an object passed to the function. Try this in an ES2015

i want to parse something like this in my lexer: ( begin expression ) where expressions are also surrounded by brackets. it isn't important what is in the expression, i just want to have all what's between the (begin and the matching ) as a token. an example would be: (begin (define x (+ 1 2))) so the text of the token should be (define x (+ 1 2))) something like PROGRAM : LPAREN BEGIN .* RPAREN; does (obviously) not work because as soon as he sees a ")", he thinks the rule is over, but i need the matching bracket for this. how can i do that? Bart Kiers Inside lexer rules, you can invoke rules

I am writing code to generate a random 3 letter strings using the letters a, b, and c. I am getting the error message "Syntax error on token ";", { expected after this token" after the line where i create the random variable (Random rand = new Random();). I do not know why I am getting this error when it looks fine to me. I am also getting the error message: Syntax error, insert "}" to complete ClassBody, after the last bracket in the program. I am almost postive all my closing brackets match up so I do not know where this error is coming from. PLEASE HELP!! import java.util.*; public class

Source: [This] is some text with [some [blocks that are nested [in a [variety] of ways]]] Resultant text: [This] is some text with I don't think you can do a regex for this, from looking at the threads at stack overflow . Is there a simple way to to do this -> or must one reach for pyparsing (or other parsing library)? Taking the OP's example as normative (any block including further nested blocks must be removed), what about...: import itertools x = '''[This] is some text with [some [blocks that are nested [in a [variety] of ways]]] and some [which are not], and [any [with nesting] must go]

I have been using this /\(\s*([^)]+?)\s*\)/ regex to remove outer brackets with PHP preg_replace function (Read more in my previous question Regex to match any character except trailing spaces ). This works fine when there is only one pair of brackets, but problem is when there is more, for example ( test1 t3() test2) becomes test1 t3( test2) instead test1 t3() test2 . I am aware of regex limitations, but it would be nice if I could just make it not matching anything if there is more then one pair of brackets. So, example behavior is good enough: ( test1 test2 ) => test1 test2 ( test1 t3()

We use braces {} for variable expression like NAME="test" FILE_NAME=${NAME}file But I don't understand in which scenarios we use brackets () Say nslookup $(hostname) works only with () brackets. Can someone explain? Minor nitpick first: Brackets [] Parentheses () Braces {} (Double) Quotation marks "" (Single) Quotation marks (apostrophes) '' Backticks `` (Same as the tilde ~ key) Braces are used in BASh scripts for complex variable expansion. Consider string concatenation: STR="hello" STR2=$STR STR2 evaluates to "hello". What if you wanted to make it something like "helloWorld". Doing

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: i.e. $text = 'remove this text (keep this text and 123)'; echo preg_replace('', '', $text); It should output: (keep this text and 123) 回答1: Take anything found within the brackets, put it in a capture group and keep that only, like this: echo preg_replace('/^.*(\(.*\)).*$/', '$1', $text); 回答2: This will do it: (and works with nested () as well) $re = '/[^()]*+(\((?:[^()]++|(?1))*\))[^()]*+/'; $text = preg_replace($re, '$1', $text); Here are a couple test cases: Input: Non-nested case: 'remove1 (keep1) remove2 (keep2) remove3' Nested case:

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a service in my angular app that looks something like this: angular.module('BracketService', []).factory('BracketService', [function() { function compareByWeight(a, b) { return a.weight - b.weight; } function filterWeightGroup(competitors, lowWeight, highWeight) { //filter stuff } function createBracketsByWeightGroup(weightGroup) { //create some brackets } //set some base line values var SUPER_HEAVY_WEIGHT = 500; var SUPER_LIGHT_WEIGHT = 20; return { //create brackets from a list of competitors returnBrackets: function(competitors) {