Hi all:
What's the intent of () inside the regex? Thanks.
pattern.replace(/\{(\d+)\}/g,
function(pattern, index) {
return args[index].toString();
});
PS: args is something like ["3", "dl1", "42"]
views:
39answers:
2something like ["3", "dl1", "42"]
Ricky
2010-09-30 08:48:57
Hi, what's the purpose to create groups here?
Ricky
2010-09-30 09:09:35
+4
A:
It is used to manage grouping.
The purpose of grouping is to make backreferences on searches & replaces. Using regex you can make that Jhon Doe becomes Doe, Jhon.
To achieve that, you would use a Regex (\w*) (\w*) with two grups, and replace it for $2, $1
Usually, the first group (0) references the whole match of the regex, being the other groups numbered according to the order where they are in your expression.
SoulWanderer
2010-09-30 08:33:30
+1: But I would add that not all groups are capturing groups. Some just affect the operation of *,+,?,| etc
CurtainDog
2010-09-30 08:40:59
I use a regex (Java format, it is quite similar to Javascript) to parse jdbc oracle connection chain:`jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521))(CONNECT_DATA=(SID = sidbbdd))`I need it to fin the host, so I would write`.*@.*HOST=(\w*)\).*`This regex will ignore pretty much everything until it finds `HOST=` then, it will find everything until it finds `)` and ignore the rest of the chain.To reference the part of my host I would use $1, which would return `test`.
SoulWanderer
2010-09-30 09:11:30
Should I need further matchings of subsets of the regex, I would use more groups, for instance`(.*@.*)HOST=(\w*)\)(.*)`would return:$0 --> `jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=test)(PORT=1521))(CONNECT_DATA=(SID = sidbbdd))`$1 --> `jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(`$2 --> `test`$3 --> `(PORT=1521))(CONNECT_DATA=(SID = sidbbdd))`
SoulWanderer
2010-09-30 09:16:34