How can I split a string into segments of n characters?

Clear look at the magical RegEx

Getting into the groove with RegEx

The core engine for our tandem bike here is the regex pattern /.{1,n}/g. This snazzy pattern matches one to n characters in the string all the way to the end!

Embracing newlines and special characters

Changing gears to allow newlines and special characters? Replace the simple dot with [\s\S]:

const regexPattern = new RegExp(`[\\s\\S]{1,${n}}`, 'g');
const segments = herMajestyTheString.match(regexPattern) || [];
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Villain null's got nothing!

Ever bumped into a null when your precious function found nothing to match? Fret not, || [] safeguards your functions, returning you an empty array instead.

Tailoring your suit (or in this case, your pattern!)

Potter around with the edge cases and meet odd lengths half-way. If the string length isn't playing ball with n, the last segment ensnares the remainder.

Non-regex approach: guys, it's not rocket science!

Good old for-loop: ever so reliable

Ring the bell and let's call the for-loop forward to help with substring extraction:

function splitStringNonRegex(str, n) {
  var result = [];
  // Looping over your string like an atypical JavaScript rockstar 
  for (var i = 0; i < str.length; i += n) {
    result.push(str.substring(i, i + n));
  }
  return result;
  // See result? It's the array. Not something to swear by, but hey, it works! 
}
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The simplicity and clarity of this approach would make your coding grandma proud.

Think about this!

Arm wrestle with unicodes and emojis

JavaScript sings duets with UCS-2 encoding, meaning that special surrogate pairs may sneak past simple splitting. Keep libraries like lodash/chunk at the ready for all strings with complex characters such as emoji.

Regex: Ultron version

Lookbehind assertions, anyone? They stops breakages at specified points:

/(?<=^(?:.{n})+)(?!$)/
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This pattern handles segmented data delicately but needs some JavaScript environments adjustments.

Going above and beyond

Wanna see your segments?

See what you’re working with:

const visualisedSegments = zeString.replace(new RegExp(`(.{${n}})`, 'g'), '$1-');
// Adding a dash - a line really - to your carpentry work.
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Overlapping segments? No more!

Use non-capturing groups (?:...) to ensure discreet segmentation:

const pattern = new RegExp(`(?:.{${n}})(?!$)`, 'g');
// capturing n characters but not the string ending. Get it? Got it? Good!
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Empty array magic

An empty array makes an amazing placeholder if you need your segments to perform tricks:

let segments = Array.from({ length: Math.ceil(str.length / n) }, () => '');
// Ready! Empty strings awaiting their debut. 
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