PHP截断函数

Posted 2021-02-26

Hey everyone, I was noticing that there are a lot of ways that people are using to write their own string truncation functions wit the use of other functions like 'substr_replace', but it kinda seemed like a lot of them went a bit too far out to make any sense to a n00b. Not that I am one anymore, but I though I'd add a note on this topic myself, in hopes that it might help others understand things a little better.

Here's a concept that some people don't know about, or remember to use often enough; You can actually pull individual characters out of a string by referencing that string as though it were an array. Example: If I have the string $s = 'cat', I can use $s[0] to actually get out only the first character of that string, 'c'. I use that same principle below, but I just use a loop to iterate through a string and add the characters to the output variable one by one until the $lenth param has been reached, or until the end of the string.

I hope this can help someone out!

-Admiral Potato

<?php
 
function admiralsTruncate($string, $length){
	settype($string, 'string');
	settype($length, 'integer');
	for($a = 0; $a < $length AND $a < strlen($string); $a++){
		$output .= $string[$a];
	}
	return($output);
}
 
 
$my_string = 'cfcd208495d565ef66e7dff9f98764da';
 
echo admiralsTruncate($my_string, 6);    // outputs: cfcd20
 
echo '<br>';
 
echo admiralsTruncate($my_string, 9);    // outputs: cfcd20849
 
?>