dollar-sign - w3toppers.com

How to escape dollar sign ($) in a string using perl regex

Try this: my %special_characters; $special_characters{“_”} = “\\_”; $special_characters{“\\\$”} = “\\\$”; $special_characters{“{“} = “\\{“; $special_characters{“}”} = “\\}”; $special_characters{“#”} = “\\#”; $special_characters{“%”} = “\\%”; $special_characters{“&”} = “\\&”; Looks weird, right? Your regex needs to look as follows: s/\$/\$/g In the first part of the regex, “$” needs to be escaped, because it’s a special regex character denoting … Read more

How to echo a variable containing an unescaped dollar sign in bash

The problem is that script receives “test1” in the first place and it cannot possibly know that there was a reference to an empty (undeclared) variable. You have to escape the $ before passing it to the script, like this: ./script.sh “test1\$test2” Or use single quotes ‘ like this: ./script.sh ‘test1$test2’ In which case bash … Read more

Dollar sign before a variable

To access a column, use: my_data[ , cond] or my_data[[cond]] The ith row can be accessed with: my_data[i, ] Combine both to obtain the desired value: my_data[i, cond] or my_data[[cond]][i]

When/why to prefix variables with “$” when using jQuery? [duplicate]

It’s a common reference to a jQuery wrapped object. It makes reading the code easier to know which variables are jQuery wrapped. //Item has been “cached” for later use in the script as a jQuery object. var $item = $(this);

What does $ mean/do in Haskell?

$ is infix “application”. It’s defined as ($) :: (a -> b) -> (a -> b) f $ x = f x — or ($) f x = f x — or ($) = id It’s useful for avoiding extra parentheses: f (g x) == f $ g x. A particularly useful location for it … Read more

jQuery dollar sign ($) as function argument?

When you see: (function() { // all JS code here })(); It is knows as self-invoking anonymous function. The function executes as soon as it is parsed because of the addition of () at the end (that’s how you run js functions). Notice that extra outer braces are just convention, you could also write it … Read more

$ Variable (Dollar Sign) in Chrome?

This has changed yet again, even since just last year. The devtools console provides $ as an alias to document.querySelector, along with many other things; here’s an excerpted list: $(selector) returns the reference to the first DOM element with the specified CSS selector. This function is an alias for the document.querySelector() function. $$(selector) returns an … Read more

What are ‘$$’ used for in PL/pgSQL

These dollar signs ($$) are used for dollar quoting, which is in no way specific to function definitions. It can be used to replace single quotes enclosing string literals (constants) anywhere in SQL scripts. The body of a function happens to be such a string literal. Dollar-quoting is a PostgreSQL-specific substitute for single quotes to … Read more

What are the special dollar sign shell variables?

$1, $2, $3, … are the positional parameters. “$@” is an array-like construct of all positional parameters, {$1, $2, $3 …}. “$*” is the IFS expansion of all positional parameters, $1 $2 $3 …. $# is the number of positional parameters. $- current options set for the shell. $$ pid of the current shell (not … Read more