正则表达式以匹配以特定字符串开头并以特定字符串结尾的字符串的内容

Question

How can I make a regex that would extract the the contents of the first square brackets in the following?

Block[first_name][value] returns the string first_name .

Block[last_name][value] returns the string last_name .

What I've tried:

This was my current regex: http://regex101.com/r/jW0hY1/1

/(?:Block\\[).*(?:\\[value])/

I figured first I'd have a non-capturing match for Block[ . Then I would capture all the content until ][value] began. Instead this seems to return the entire string.

Answer 1

Get the matched group from index 1.

(?:Block\[)([^\]]*)(?:\]\[value\])

DEMO

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OR make some changes in your regex

(?:Block\[)(.*)(?:\]\[value])

DEMO

Answer 2

The problem is that .* eats up as many characters as it can. Use a non greedy quantifier instead, and a capture group:

Block\[(.*?)\]

If you need to capture the value too, you can use this expression:

Block\[(.*?)\]\[(.*?)\]

EDIT: And the JS...

var re = /Block\[(.*?)\]\[(.*?)\]/g;
var match;
while(match = re.exec("Block[first_name][value] Block[last_name][value]")) {
    console.log("Found " + match[1] + " with value: " + match[2]);
}

Answer 3

Regular expression: ( DEMO )

(?:Block\[)(.*)(?:\]\[value])

Getting the content:

string = "Block[first_name][value]";
result = string.match((/?:Block\[)(.*)(?:\]\[value])/, g);
console.log(result[1]); //first_name