Hey all, what would the regEX code be for the following:
<br/><span class=""synopsis-view-synopsis"">America's justice system comes under indictment in director <a href='/people/1035' class='actor' style='font-weight:bold'>Norman Jewison</a>'s trenchant film starring <a href='/people/1028' class='actor' style='font-weight:bold'>Al Pacino</a> as upstanding attorney Arthur Kirkland. A hard-line -- and tainted -- judge (<a href='/people/1034' class='actor' style='font-weight:bold'>John Forsythe</a>) stands accused of rape, and Kirkland (<a href='/people/1028' class='actor' style='font-weight:bold'>Al Pacino</a>) has to defend him. Kirkland has a history with the judge, who jailed one of the lawyer's clients on a technicality. When the judge confesses his guilt, Kirkland faces an ethical and legal quandary. </span>
Ive tried this:
regex = New System.Text.RegularExpressions.Regex("(?<=""synopsis-view-synopsis""\>)([^<\/span><]+)")
But that only seems to get the first part of the description; Americ
Any help would be great! :o)
David
I don't see any need for lookaheads or lookbehinds here; just match the whole <span> element and use a capturing group extract its content. Assuming there will never be any <span> elements inside the one you're matching, this should be all you need:
Regex rgx = new Regex(
#"<span\s+class=""synopsis-view-synopsis"">(.*?)</span>",
RegexOptions.IgnoreCase | RegexOptions.Singleline);
foreach (Match m in rgx.Matches(s0))
{
Console.WriteLine(m.Groups[1].Value);
}
Also, [^<\/span><]+ doesn't do what you probably think it does. What you've got there is a character class that matches any one character except <, /, s, p, a, n, or >. You may have been trying for this:
(?:(?!</span>).)+
...which matches one character at a time, after the lookahead confirms that the character isn't the beginning of the sequence </span>. It's a valid technique, but (as with the lookarounds) I don't think you need anything so fancy here.
(?=""synopsis-view-synopsis""\>).+(?!<\/span>)
Should probably work. Try using an HTML parser instead!
in .net there are different methods for "match" and "matches all" these are:
re.Match(str); // regex 're' match in string 'str'
re.Matches(str) // regex 're' matches all in string 'str'
update
Explain to regex
(?<=regex) is positive lookbehind
(?!regex) is a negativ lookahead
.+ finally matches anything between the lookaround
Raw Match Pattern:
(?<=""synopsis-view-synopsis""\>).+(?!</span>)
C#.NET Code Example:
using System;
using System.Text.RegularExpressions;
namespace myapp
{
class Class1
{
static void Main(string[] args)
{
String sourcestring =
"<br/><span class=""synopsis-view-synopsis"">America's justice... </span>
<br/><span class=""synopsis-view-synopsis"">Canada's justice... </span>";
Regex re = new Regex(#"(?<=""""synopsis-view-synopsis""""\>).+(?!</span>)");
MatchCollection mc = re.Matches(sourcestring);
int mIdx=0;
foreach (Match m in mc)
{
for (int gIdx = 0; gIdx < m.Groups.Count; gIdx++)
{
Console.WriteLine("[{0}][{1}] = {2}", mIdx, re.GetGroupNames()[gIdx], m.Groups[gIdx].Value);
}
mIdx++;
}
}
}
}
Matches Found:
[0][0] = America's justice... </span>
[1][0] = Canada's justice... </span>
Related
What is the regular expression (in JavaScript if it matters) to only match if the text is an exact match? That is, there should be no extra characters at other end of the string.
For example, if I'm trying to match for abc, then 1abc1, 1abc, and abc1 would not match.
Use the start and end delimiters: ^abc$
It depends. You could
string.match(/^abc$/)
But that would not match the following string: 'the first 3 letters of the alphabet are abc. not abc123'
I think you would want to use \b (word boundaries):
var str = 'the first 3 letters of the alphabet are abc. not abc123';
var pat = /\b(abc)\b/g;
console.log(str.match(pat));
Live example: http://jsfiddle.net/uu5VJ/
If the former solution works for you, I would advise against using it.
That means you may have something like the following:
var strs = ['abc', 'abc1', 'abc2']
for (var i = 0; i < strs.length; i++) {
if (strs[i] == 'abc') {
//do something
}
else {
//do something else
}
}
While you could use
if (str[i].match(/^abc$/g)) {
//do something
}
It would be considerably more resource-intensive. For me, a general rule of thumb is for a simple string comparison use a conditional expression, for a more dynamic pattern use a regular expression.
More on JavaScript regexes: https://developer.mozilla.org/en/JavaScript/Guide/Regular_Expressions
"^" For the begining of the line "$" for the end of it. Eg.:
var re = /^abc$/;
Would match "abc" but not "1abc" or "abc1". You can learn more at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
I would like to grab the first 4 characters of two words using RegEx. I have some RegEx experinece however a search did not yeild any results.
So if I have Awesome Sauce I would like the end result to be AwesSauc
Use the Replace Text action with the following parameters:
Pattern: \W*\b(\p{L}{1,4})\w*\W*
Replacement text: $1
See the regex demo.
Pattern details:
\W* - 0+ non-word chars (trim from the left)
\b - a leading word boundary
(\p{L}{1,4}) - Group 1 (later referred to via $1 backreference) matching any 1 to 4 letters (incl. Unicode ones)
\w* - any 0+ word chars (to match the rest of the word)
\W* - 0+ non-word chars (trim from the right)
I think this RegEx should do the job
string pattern = #"\b\w{4}";
var text = "The quick brown fox jumps over the lazy dog";
Regex regex = new Regex(pattern);
var match = regex.Match(text);
while (match.Captures.Count != 0)
{
foreach (var capture in match.Captures)
{
Console.WriteLine(capture);
}
match = match.NextMatch();
}
// outputs:
// quic
// brow
// jump
// over
// lazy
Alternatively you could use patterns like:
\b\w{1,4} => The, quic, brow, fox, jump, over, the, lazy, dog
\b[\w|\d]{1,4} => would also match digits
Update:
added a full example for C# and modified the pattern slightly. Also added some alternative patterns.
one approach with Linq
var res = new string(input.Split().SelectMany((x => x.Where((y, i) => i < 4))).ToArray());
Try this expression
\b[a-zA-Z0-9]{1,4}
Using regex would in fact be more complex and totally unnecessary for this case. Just do it as either of the below.
var sentence = "Awesome Sau";
// With LINQ
var linqWay = string.Join("", sentence.Split(" ".ToCharArray(), options:StringSplitOptions.RemoveEmptyEntries).Select(x => x.Substring(0, Math.Min(4,x.Length))).ToArray());
// Without LINQ
var oldWay = new StringBuilder();
string[] words = sentence.Split(" ".ToCharArray(), options:StringSplitOptions.RemoveEmptyEntries);
foreach(var word in words) {
oldWay.Append(word.Substring(0, Math.Min(4, word.Length)));
}
Edit:
Updated code based on #Dai's comment. Math.Min check borrowed as is from his suggestion.
What is the regular expression (in JavaScript if it matters) to only match if the text is an exact match? That is, there should be no extra characters at other end of the string.
For example, if I'm trying to match for abc, then 1abc1, 1abc, and abc1 would not match.
Use the start and end delimiters: ^abc$
It depends. You could
string.match(/^abc$/)
But that would not match the following string: 'the first 3 letters of the alphabet are abc. not abc123'
I think you would want to use \b (word boundaries):
var str = 'the first 3 letters of the alphabet are abc. not abc123';
var pat = /\b(abc)\b/g;
console.log(str.match(pat));
Live example: http://jsfiddle.net/uu5VJ/
If the former solution works for you, I would advise against using it.
That means you may have something like the following:
var strs = ['abc', 'abc1', 'abc2']
for (var i = 0; i < strs.length; i++) {
if (strs[i] == 'abc') {
//do something
}
else {
//do something else
}
}
While you could use
if (str[i].match(/^abc$/g)) {
//do something
}
It would be considerably more resource-intensive. For me, a general rule of thumb is for a simple string comparison use a conditional expression, for a more dynamic pattern use a regular expression.
More on JavaScript regexes: https://developer.mozilla.org/en/JavaScript/Guide/Regular_Expressions
"^" For the begining of the line "$" for the end of it. Eg.:
var re = /^abc$/;
Would match "abc" but not "1abc" or "abc1". You can learn more at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
What is the regular expression (in JavaScript if it matters) to only match if the text is an exact match? That is, there should be no extra characters at other end of the string.
For example, if I'm trying to match for abc, then 1abc1, 1abc, and abc1 would not match.
Use the start and end delimiters: ^abc$
It depends. You could
string.match(/^abc$/)
But that would not match the following string: 'the first 3 letters of the alphabet are abc. not abc123'
I think you would want to use \b (word boundaries):
var str = 'the first 3 letters of the alphabet are abc. not abc123';
var pat = /\b(abc)\b/g;
console.log(str.match(pat));
Live example: http://jsfiddle.net/uu5VJ/
If the former solution works for you, I would advise against using it.
That means you may have something like the following:
var strs = ['abc', 'abc1', 'abc2']
for (var i = 0; i < strs.length; i++) {
if (strs[i] == 'abc') {
//do something
}
else {
//do something else
}
}
While you could use
if (str[i].match(/^abc$/g)) {
//do something
}
It would be considerably more resource-intensive. For me, a general rule of thumb is for a simple string comparison use a conditional expression, for a more dynamic pattern use a regular expression.
More on JavaScript regexes: https://developer.mozilla.org/en/JavaScript/Guide/Regular_Expressions
"^" For the begining of the line "$" for the end of it. Eg.:
var re = /^abc$/;
Would match "abc" but not "1abc" or "abc1". You can learn more at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
I am trying to replace a certain group to "" by using regex.
I was searching and doing my best, but it's over my head.
What I want to do is,
string text = "(12je)apple(/)(jj92)banana(/)cat";
string resultIwant = {apple, banana, cat};
In the first square bracket, there must be 4 character including numbers.
and '(/)' will come to close.
Here's my code. (I was using matches function)
string text= #"(12dj)apple(/)(88j1)banana(/)cat";
string pattern = #"\(.{4}\)(?<value>.+?)\(/\)";
Regex rex = new Regex(pattern);
MatchCollection mc = rex.Matches(text);
if(mc.Count > 0)
{
foreach(Match str in mc)
{
print(str.Groups["value"].Value.ToString());
}
}
However, the result was
apple
banana
So I think I should use replace or something else instead of Matches.
The below regex would capture the word characters which are just after to ),
(?<=\))(\w+)
DEMO
Your c# code would be,
{
string str = "(12je)apple(/)(jj92)banana(/)cat";
Regex rgx = new Regex(#"(?<=\))(\w+)");
foreach (Match m in rgx.Matches(str))
Console.WriteLine(m.Groups[1].Value);
}
IDEONE
Explanation:
(?<=\)) Positive lookbehind is used here. It sets the matching marker just after to the ) symbol.
() capturing groups.
\w+ Then it captures all the following word characters. It won't capture the following ( symbol because it isn't a word character.