CODEWITHSUNDEEP
javascriptregexstringsplit
NikiT
NikiT

Reputation: 38

How do I correctly apply regex so array does not have empty string at the start

I'm struggling with a regex.

I am able to split the string at the required location, but when it is added to an array, the array has an empty string at the start.

// This is the string I am wanting to split.
// I want the first 4 words to be separated from the remainder of the string
const chatMessage = "This is a string that I want to split";

// I am using this regex
const r = /(^(?:\S+\s+\n?){4})/;

const chatMessageArr = chatMessage.split(r);

console.log(chatMessageArr);

It returns:

[ '', 'This is a string ', 'that I want to split' ]

But need it to return:

[ 'This is a string ', 'that I want to split' ]

Upvotes: 0

Views: 45

Answers (2)

Barmar
Barmar

Reputation: 780909

Add a second capture group to the regexp and use .match() instead of .split().

// This is the string I am wanting to split.
// I want the first 4 words to be separated from the remainder of the string
const chatMessage = "This is a string that I want to split";

// I am using this regex
const r = /(^(?:\S+\s+\n?){4})(.*)/;

const chatMessageArr = chatMessage.match(r);
chatMessageArr.shift(); // remove the full match

console.log(chatMessageArr);

Upvotes: 0

Tim Biegeleisen
Tim Biegeleisen

Reputation: 521178

I wouldn't use string split here, I would use a regex replacement:

var chatMessage = "This is a string that I want to split";
var first = chatMessage.replace(/^\s*(\S+(?:\s+\S+){3}).*$/, "$1");
var last = chatMessage.replace(/^\s*\S+(?:\s+\S+){3}\s+(.*$)/, "$1");
console.log(chatMessage);
console.log(first);
console.log(last);

Upvotes: 1

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