How to extract a string from parent string?

Question

I have a string url as follows:

var url = '/test/mybin/processes/edit.jsp?id={processId}';

I want to extract the string "processId" from above url. I can get it using indexOf and substring methods, but is there a better alternative to do it? Can we do it using Regex?

for such a simple string deconstruction, use string operations. regex is massive overkill. — Marc B, Sep 16 '14 at 18:30
possible duplicate of [How can I get query string values in JavaScript?](http://stackoverflow.com/questions/901115/how-can-i-get-query-string-values-in-javascript) — Waxen, Sep 16 '14 at 18:44
Thanks a lot, everyone. Most of the sugeestions below work. ,But I would like to know which is the best option from performance aspect? Using Regex or match or indexOf/substring? — user3792795, Sep 16 '14 at 18:46
Why the concern about performance? Is that an operation your application is going to repeat gazillions of times in a short period? — Alexis Pigeon, Sep 27 '14 at 15:52

score 1 · Answer 1 · answered Sep 16 '14 at 18:31

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var procid = url.split("id=")[1];

answered Sep 16 '14 at 18:31

BReal14

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This will include the braces in the extracted string, which is not what OP wants. – Ted Hopp Sep 16 '14 at 18:35
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Yes, it will. I assumed the brackets were to exemplify a variable – BReal14 Sep 16 '14 at 18:53

comdiv · Answer 2 · 2014-09-16T18:36:27.897

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JavaScript strings has regex support embeded:

var processId = url.match(/\?id=(.+)/)[1];

Only thing U need - be familiar with regular expressions

And if braces are problem:

var processId = url.match(/\?id=\{(.+)\}/)[1];

edited Sep 16 '14 at 18:36

answered Sep 16 '14 at 18:30

comdiv

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I tried this and it gave me {processId}. What I want is processId – user3792795 Sep 16 '14 at 18:34
This will include the braces in the extracted string, which is not what OP wants. – Ted Hopp Sep 16 '14 at 18:34
Thought that braces was just as placeholders ) var processId = url.match(/\?id=\{(.+)\}/)[1]; – comdiv Sep 16 '14 at 18:35

score 0 · Answer 3 · answered Sep 16 '14 at 18:32

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'/test/mybin/processes/edit.jsp?id={processId}'.split('{')[1].split('}')[0]

answered Sep 16 '14 at 18:32

sabithpocker

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Ypu should actually try it yourself, just get the concept of using `split` and `join` – sabithpocker Sep 16 '14 at 18:34

score 0 · Accepted Answer · answered Sep 16 '14 at 18:33

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You can easily use a regex:

url.match(/\{([^}]*)\}/)[1];

But for this simple pattern, using indexOf and substring, while not as terse, will have much better performance. TIMTOWTDI

answered Sep 16 '14 at 18:33

Ted Hopp

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How to extract a string from parent string?

4 Answers4