Splitting a string at special character with JavaScript

Question

I am trying to "intelligently" pre-fill a form, I want to prefill the firstname and lastname inputs based on a user email address, so for example,

jon.doe@email.com RETURNS Jon Doe
jon_doe@email.com RETURN Jon Doe
jon-doe@email.com RETURNS Jon Doe

I have managed to get the string before the @,

var email = letters.substr(0, letters.indexOf('@'));

But cant work out how to split() when the separator can be multiple values, I can do this,

email.split("_")

but how can I split on other email address valid special characters?

What's a "special character"? Notice that all characters are valid in an email address. — Bergi, Aug 12 '14 at 14:13

score 17 · Accepted Answer · answered Aug 12 '14 at 14:10

17

JavaScript's string split method can take a regex.

For example the following will split on ., -, and _.

"i-am_john.doe".split(/[.\-_]/)

Returning the following.

["i", "am", "john", "doe"]

answered Aug 12 '14 at 14:10

Alexander O'Mara

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score 4 · Answer 2 · answered Aug 12 '14 at 14:09

4

You can use a regular expression for what you want to split on. You can for example split on anything that isn't a letter:

var parts = email.split(/[^A-Za-z]/);

Demo: http://jsfiddle.net/Guffa/xt3Lb9e6/

answered Aug 12 '14 at 14:09

Guffa

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furydevoid · Answer 3 · 2014-08-12T14:36:39.263

1

Regular Expressions --

email.split(/[_\.-]/)

This one matches (therefore splits at) any of (a character set, indicated by []) _, ., or -.

Here's a good resource for learning regular expressions: http://qntm.org/files/re/re.html

edited Aug 12 '14 at 14:36

answered Aug 12 '14 at 14:10

furydevoid

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You should offer some more explanation of your answer – Cfreak Aug 12 '14 at 14:32

Kara Brightwell · Answer 4 · 2014-08-12T14:16:12.657

You can split a string using a regular expression. To match ., _ or -, you can use a character class, for example [.\-_]. The syntax for regular expressions in JavaScript is /expression/, so your example would look like:

email.split(/[\.\-_]/);

Note that the backslashes are to prevent . and - being interpreted as special characters. . is a special character class representing any character. In a character class, - can be used to specify ranges, such as [a-z].

If you require a dynamic list of characters to split on, you can build a regular expression using the RegExp constructor. For example:

var specialChars = ['.', '\\-', '_'];
var specialRegex = new RegExp('[' + specialChars.join('') + ']');
email.split(specialRegex);

More information on regular expressions in JavaScript can be found on MDN.

score 0 · Answer 5 · answered Aug 12 '14 at 14:09

0

You can use regex to do it, just provide a list of the characters in square brackets and escape if necessary.

email.split("[_-\.]");

Is that what you mean?

answered Aug 12 '14 at 14:09

Zyga

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If you want to pass in a regular expression, it cannot be a string literal. ```split("[_-\.]");``` will split on the exact, full sequence ```[_-\.]```. – furydevoid Aug 12 '14 at 14:41

score 0 · Answer 6 · answered Aug 12 '14 at 14:11

You are correct that you need to use the split function.

Split function works by taking an argument to split the string on. Multiple values can be split via regular expression. For you usage, try something like

var re = /[\._\-]/;
var split = email.split(re, 2);

This should result in an array with two values, first/second name. The second argument is the number of elements returned.

score 0 · Answer 7 · answered Aug 12 '14 at 14:15

I created a jsFiddle to show how this could be done :

function printName(email){
    var name = email.split('@')[0];
    // source : http://stackoverflow.com/questions/650022/how-do-i-split-a-string-with-multiple-separators-in-javascript
    var returnVal = name.split(/[._-]/g);
    return returnVal;
}

http://jsfiddle.net/ts6nx9tt/1/

score 0 · Answer 8 · answered Aug 12 '14 at 14:16

If you define your seperators, below code can return all alternatives for you.

var arr = ["_",".","-"];

var email = letters.substr(0, letters.indexOf('@'));
arr.map(function(val,index,rest){
   var r = email.split(val);
   if(r.length > 1){
     return r.join(' ');
   }
   return "";
}
);

Splitting a string at special character with JavaScript

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