[javascript] How to make Regular expression into non-greedy?

I'm using jQuery. I have a string with a block of special characters (begin and end). I want get the text from that special characters block. I used a regular expression object for in-string finding. But how can I tell jQuery to find multiple results when have two special character or more?

My HTML:

<div id="container">
    <div id="textcontainer">
     Cu?c chi?n pháp lý gi?a [|co th?|nghi?m|] th? tru?ng [|test2|dây là test l?n 2|] ch?ng khoán [|M?|day la nuoc my|] và ngân hàng d?u tu quy?n l?c nh?t Ph? Wall m?i ch? b?t d?u.
    </div>
</div>

and my JavaScript code:

$(document).ready(function() {
  var takedata = $("#textcontainer").text();
  var test = 'abcd adddb';
  var filterdata = takedata.match(/(\[.+\])/);

  alert(filterdata); 

  //end write js 
});

My result is: [|co th?|nghi?m|] th? tru?ng [|test2|dây là test l?n 2|] ch?ng khoán [|M?|day la nuoc my|] . But this isn't the result I want :(. How to get [text] for times 1 and [demo] for times 2 ?

I've just done my work after searching info on internet ^^. I make code like this:

var filterdata = takedata.match(/(\[.*?\])/g);

• my result is : [|co th?|nghi?m|],[|test2|dây là test l?n 2|] this is right!. but I don't really understand this. Can you answer my why?

You are right that greediness is an issue:

--A--Z--A--Z--
  ^^^^^^^^^^
     A.*Z

If you want to match both A--Z, you'd have to use A.*?Z (the ? makes the * "reluctant", or lazy).

There are sometimes better ways to do this, though, e.g.

A[^Z]*+Z

This uses negated character class and possessive quantifier, to reduce backtracking, and is likely to be more efficient.

In your case, the regex would be:

/(\[[^\]]++\])/

Unfortunately Javascript regex doesn't support possessive quantifier, so you'd just have to do with:

/(\[[^\]]+\])/

See also

• regular-expressions.info/Repetition
  • See: An Alternative to Laziness
    • Possessive quantifiers
  • Flavors comparison

Quick summary

*   Zero or more, greedy
*?  Zero or more, reluctant
*+  Zero or more, possessive

+   One or more, greedy
+?  One or more, reluctant
++  One or more, possessive

?   Zero or one, greedy
??  Zero or one, reluctant
?+  Zero or one, possessive

Note that the reluctant and possessive quantifiers are also applicable to the finite repetition {n,m} constructs.

Examples in Java:

System.out.println("aAoZbAoZc".replaceAll("A.*Z", "!"));  // prints "a!c"
System.out.println("aAoZbAoZc".replaceAll("A.*?Z", "!")); // prints "a!b!c"

System.out.println("xxxxxx".replaceAll("x{3,5}", "Y"));  // prints "Yx"
System.out.println("xxxxxx".replaceAll("x{3,5}?", "Y")); // prints "YY"

I believe it would be like this

takedata.match(/(\[.+\])/g);

the g at the end means global, so it doesn't stop at the first match.