Truncating Text in PHP? [closed]

问题:

I'm trying to truncate some text in PHP and have stumbled across this method (http://theodin.co.uk/blog/development/truncate-text-in-php-the-easy-way.html), which judging by the comments seems like a great easy-to-implement solution. The problem is I don't know how to implement it :S.

Would someone mind pointing me in the direction of what to do to implement this? Any help whatsoever would be appreciated.

Thanks in advance.

回答1:

The obvious thing to do is read the documentation.

But to help: substr($str, $start, $end);

$str is your text

$start is the character index to begin at. In your case, it is likely 0 which means the very beginning.

$end is where to truncate at. Suppose you wanted to end at 15 characters, for example. You would write it like this:

<?php

$text = "long text that should be truncated";
echo substr($text, 0, 15);

?>

and you would get this:

long text that 

makes sense?

EDIT

The link you gave is a function to find the last white space after chopping text to a desired length so you don't cut off in the middle of a word. However, it is missing one important thing - the desired length to be passed to the function instead of always assuming you want it to be 25 characters. So here's the updated version:

function truncate($text, $chars = 25) {
    if (strlen($text) <= $chars) {
        return $text;
    }
    $text = $text." ";
    $text = substr($text,0,$chars);
    $text = substr($text,0,strrpos($text,' '));
    $text = $text."...";
    return $text;
}

So in your case you would paste this function into the functions.php file and call it like this in your page:

$post = the_post();
echo truncate($post, 100);

This will chop your post down to the last occurrence of a white space before or equal to 100 characters. Obviously you can pass any number instead of 100. Whatever you need.

回答2:

$text="abc1234567890";

// truncate to 4 chars

echo substr(str_pad($text,4),0,4);

This avoids the problem of truncating a 4 char string to 10 chars .. (i.e. source is smaller than the required)

回答3:

$mystring = "this is the text I would like to truncate";

// Pass your variable to the function
$mystring = truncate($mystring);

// Truncated tring printed out;
echo $mystring;

//truncate text function
public function truncate($text) {

    //specify number fo characters to shorten by
    $chars = 25;

    $text = $text." ";
    $text = substr($text,0,$chars);
    $text = substr($text,0,strrpos($text,' '));
    $text = $text."...";
    return $text;
}