parentheses

Possible Duplicate: What is the (function() { } )() construct in JavaScript? I came across this bit of JavaScript code, but I have no idea what to make out of it. Why do I get "1" when I run this code? What is this strange little appendix of (1) and why is the function wrapped in parentheses? (function(x){ delete x; return x; })(1); Howard There are a few things going on here. First is the immediately invoked function expression (IIFE) pattern: (function() { // Some code })(); This provides a way to execute some JavaScript code in its own scope. It's usually used so that any variables created

I have the following code: <?php $a = 1; $b = 2; echo "sum: " . $a + $b; echo "sum: " . ($a + $b); ?> When I execute my code I get: 2 sum: 3 Why does it fail to print the string "sum:" in the first echo? It seems to be fine when the addition is enclosed in parentheses. Is this weird behaviour anywhere documented? mgibsonbr Both operators the addition + operator and the concatenation . operator have the same operator precedence , but since they are left associative they get evaluated like the following: echo (("sum:" . $a) + $b); echo ("sum:" . ($a + $b)); So your first line does the

I'm just wondering how I could remove the text between a set of parentheses and the parentheses themselves in php. Example : ABC (Test1) I would like it to delete (Test1) and only leave ABC Thanks $string = "ABC (Test1)"; echo preg_replace("/\([^)]+\)/","",$string); // 'ABC ' preg_replace is a perl-based regular expression replace routine. What this script does is matches all occurrences of a opening parenthesis, followed by any number of characters not a closing parenthesis, and again followed by a closing parenthesis, and then deletes them: Regular expression breakdown: / - opening delimiter

I extracted simple example: require 'pp' x = 1..3 pp x.map do |i| {:value => i, :double => (i*2)} end pp x.map { |i| {:value => i, :double => (i*2)} } pp(x.map do |i| {:value => i, :double => (i*2)} end) pp(x.map { |i| {:value => i, :double => (i*2)} }) I am wondering why first pp produces: [1, 2, 3] While all the oders are giving: [{:value=>1, :double=>2}, {:value=>2, :double=>4}, {:value=>3, :double=>6}] I assume it has something to do with operator precedence. Where can I find good explanation? It's because you're calling pp x.map and passing a block to pp (which ignores it) As explained in