CODEWITHSUNDEEP
javascriptregex
chris Frisina
chris Frisina

Reputation: 19688

Nth word of a string using js Regex

for this, the string is:

one two three four five six seven eight nine ten

how do you select the nth word in this string?

a word in this case is a group of one or more characters, either preceded, succeeded, or surrounded by a whitespace.

Upvotes: 1

Views: 5770

Answers (9)

Prinzhorn
Prinzhorn

Reputation: 22508

Despite the answers suggesting to not use regular expressions, here's a regex solution:

var nthWord = function(str, n) {
    var m = str.match(new RegExp('^(?:\\w+\\W+){' + --n + '}(\\w+)'));

    return m && m[1];
};

You may have to adjust the expression to fit your needs. Here are some test cases https://tinker.io/31fe7/1

Upvotes: 5

Kijewski
Kijewski

Reputation: 26022

Here is a Regex-only solution, but I daresay the other answers will have a better performance.

/^(?:.+?[\s.,;]+){7}([^\s.,;]+)/.exec('one two three four five six seven eight nine ten')

I take (runs of) whitespaces, periods, commas and semicolons as word breaks. You might want to adapt that. The 7 means Nth word - 1.

To have it more "dynamic": 

var str = 'one two three four five six seven eight nine ten';
var nth = 8;
str.match('^(?:.+?[\\s.,;]+){' + (nth-1) + '}([^\\s.,;]+)'); // the backslashes escaped

Live demo: http://jsfiddle.net/WCwFQ/2/

Upvotes: 1

spaceman12
spaceman12

Reputation: 1109

    function getWord(str,pos)
    {
        var get=str.match(/\S+\S/g);
        return get[pos-1];
    }




    //Here is an example
    var str="one two three four five     six seven eight nine ten    ";
    var get_5th_word=getWord(str,5);
    alert(get_5th_word);

Its simple :)

Upvotes: 2

Braden
Braden

Reputation: 1558

Counting things is not really what you should use a regex for, instead try maybe splitting the string based on your delimiter (space in your specific case) and then accessing the n-1th index of the array.

Javascript code : 

 >"one two three four".split(" ");
 ["one", "two", "three", "four"]
 >"one two three four".split(" ")[2];
 >"three"

Upvotes: 0

Scott Sauyet
Scott Sauyet

Reputation: 50787

var nthWord = function(str, n) {
    return str.split(" ")[n - 1]; // really should have some error checking!
}

nthWord("one two three four five six seven eight nine ten", 4) // ==> "four"

Upvotes: 0

srini.venigalla
srini.venigalla

Reputation: 5145

var words = "one two three four five six seven eight nine ten".split(" ");
var nthWord = words[n];

of course, you need to check first that the nth word exists..

Upvotes: 0

newfurniturey
newfurniturey

Reputation: 38416

You can split the string on spaces, and then access it as an array:

var sentence = 'one two three four five six seven eight nine ten';
var exploded = sentence.split(' ');

// the array starts at 0, so use "- 1" of the word
var word = 3;
alert(exploded[word - 1]);

Upvotes: 0

x1a4
x1a4

Reputation: 19475

I would use split for this -

var str = "one two three four five six seven eight nine ten";

nth = str.split(/\s+/)[n - 1];

Upvotes: 4

gen_Eric
gen_Eric

Reputation: 227200

You could just split on the spaces, and grab the Xth element.

var x = 'one two three four five six seven eight nine ten';
var words = x.split(' ');
console.log(words[5]); // 'six'

Upvotes: 1

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