Truncate a String to First N Characters of a String and Add Three Dots If Any Characters Are Removed

Truncate a string to first n characters of a string and add three dots if any characters are removed

//The simple version for 10 Characters from the beginning of the string
$string = substr($string,0,10).'...';

Update:

Based on suggestion for checking length (and also ensuring similar lengths on trimmed and untrimmed strings):

$string = (strlen($string) > 13) ? substr($string,0,10).'...' : $string;

So you will get a string of max 13 characters; either 13 (or less) normal characters or 10 characters followed by '...'

Update 2:

Or as function:

function truncate($string, $length, $dots = "...") {
    return (strlen($string) > $length) ? substr($string, 0, $length - strlen($dots)) . $dots : $string;
}

Update 3:

It's been a while since I wrote this answer and I don't actually use this code any more. I prefer this function which prevents breaking the string in the middle of a word using the wordwrap function:

function truncate($string,$length=100,$append="…") {
  $string = trim($string);

  if(strlen($string) > $length) {
    $string = wordwrap($string, $length);
    $string = explode("\n", $string, 2);
    $string = $string[0] . $append;
  }

  return $string;
}

Add ... if string is too long PHP

The PHP way of doing this is simple:

$out = strlen($in) > 50 ? substr($in,0,50)."..." : $in;

But you can achieve a much nicer effect with this CSS:

.ellipsis {
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
}

Now, assuming the element has a fixed width, the browser will automatically break off and add the ... for you.

Smart way to truncate long strings

Essentially, you check the length of the given string. If it's longer than a given length n, clip it to length n (substr or slice) and add html entity … (…) to the clipped string.

Such a method looks like

function truncate(str, n){
  return (str.length > n) ? str.slice(0, n-1) + '…' : str;
};

If by 'more sophisticated' you mean truncating at the last word boundary of a string then you need an extra check.
First you clip the string to the desired length, next you clip the result of that to its last word boundary

function truncate( str, n, useWordBoundary ){
  if (str.length <= n) { return str; }
  const subString = str.slice(0, n-1); // the original check
  return (useWordBoundary 
    ? subString.slice(0, subString.lastIndexOf(" ")) 
    : subString) + "…";
};

You can extend the native String prototype with your function. In that case the str parameter should be removed and str within the function should be replaced with this:

String.prototype.truncate = String.prototype.truncate || 
function ( n, useWordBoundary ){
  if (this.length <= n) { return this; }
  const subString = this.slice(0, n-1); // the original check
  return (useWordBoundary 
    ? subString.slice(0, subString.lastIndexOf(" ")) 
    : subString) + "…";
};

More dogmatic developers may chide you strongly for that ("Don't modify objects you don't own". I wouldn't mind though).

An approach without extending the String prototype is to create
your own helper object, containing the (long) string you provide
and the beforementioned method to truncate it. That's what the snippet
below does.

const LongstringHelper = str => {
  const sliceBoundary = str => str.substr(0, str.lastIndexOf(" "));
  const truncate = (n, useWordBoundary) => 
        str.length <= n ? str : `${ useWordBoundary 
          ? sliceBoundary(str.slice(0, n - 1))
          : str.slice(0, n - 1)}…`;
  return { full: str,  truncate };
}; 
const longStr = LongstringHelper(`Lorem ipsum dolor sit amet, consectetur 
adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore 
magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation 
ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute 
irure dolor in reprehenderit in voluptate velit esse cillum dolore 
eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non 
proident, sunt in culpa qui officia deserunt mollit anim id est laborum`);

const plain = document.querySelector("#resultTruncatedPlain");
const lastWord = document.querySelector("#resultTruncatedBoundary");
plain.innerHTML = 
  longStr.truncate(+plain.dataset.truncateat, !!+plain.dataset.onword);
lastWord.innerHTML = 
  longStr.truncate(+lastWord.dataset.truncateat, !!+lastWord.dataset.onword);
document.querySelector("#resultFull").innerHTML = longStr.full;

body {
  font: normal 12px/15px verdana, arial;
}

p {
  width: 450px;
}

#resultTruncatedPlain:before {
  content: 'Truncated (plain) n='attr(data-truncateat)': ';
  color: green;
}

#resultTruncatedBoundary:before {
  content: 'Truncated (last whole word) n='attr(data-truncateat)': ';
  color: green;
}

#resultFull:before {
  content: 'Full: ';
  color: green;
}

<p id="resultTruncatedPlain" data-truncateat="120" data-onword="0"></p>
<p id="resultTruncatedBoundary" data-truncateat="120" data-onword="1"></p>
<p id="resultFull"></p>

info = (data[:75] + '..') if len(data) > 75 else data

function truncate($string, $chars = 50, $terminator = ' …') {
    $cutPos = $chars - mb_strlen($terminator);
    $boundaryPos = mb_strrpos(mb_substr($string, 0, mb_strpos($string, ' ', $cutPos)), ' ');
    return mb_substr($string, 0, $boundaryPos === false ? $cutPos : $boundaryPos) . $terminator;
}