CODEWITHSUNDEEP
javascriptsubstring
user2631534
user2631534

Reputation: 477

Javascript cut string after 3th character in string

I need to write function that returns 3strings after character ', ' so if there is none or 1 or 2 or 3 to return empty string if ', ' character is found else return 3 strings...i wrote these function but it is very cpu intensive...can be shorter and faster code?

https://jsfiddle.net/1nfyq327/

    var str = 'AAA BBB CC., DD EE, FF FF, GG GG, HH HH, II II, JJ JJ, GG GG';

    var res = str.substring(0, str.indexOf(', ', str.indexOf(', ', str.indexOf(', ')+1)+1));

    console.log(res);

Result is:

AAA BBB CC., DD EE, FF FF

Result is fine but i need faster code because it will execute on low power cpu so speed is very cruicial...

Upvotes: 0

Views: 76

Answers (3)

Nina Scholz
Nina Scholz

Reputation: 386560

You could split with a limit of String#split and join the array.

var string = 'AAA BBB CC., DD EE, FF FF, GG GG, HH HH, II II, JJ JJ, GG GG',
    result = string.split(',', 3).join(',')

console.log(result);

Upvotes: 1

apomene
apomene

Reputation: 14389

Use split , slice and join:

var str = 'AAA BBB CC., DD EE, FF FF, GG GG, HH HH, II II, JJ JJ, GG GG';


var result = str.split(',').slice(0,3).join(',');

console.log(result);

Upvotes: 1

Simon Kocurek
Simon Kocurek

Reputation: 2166

In terms of speed there is not that much you can do.
The code you wrote runs in O(n), which is the best possible time complexity for your problem.

You can play around with native functions (split(), substring()... that are implemented in c++ and therefore will run quickly) to see if one of them is faster, or rewrite it in pure javascript with a for loop. And compare the results.

In your case the best thing you can really do is write a little benchmark testing how fast your solution is and compare that. Althought there is high chance that there is something else in your code that runs slowly. :)

Upvotes: 1

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