PHP startsWith() and endsWith() functions

Question

I need two functions that would take a string and return if it starts with the specified character/string or ends with it.

For example:

$str='|apples}';

echo startsWith($str,'|'); //Returns true
echo endsWith($str,'}'); //Returns true

Answer 1

Here you go:

function startsWith($haystack,$needle,$case=true) {
    if($case){return (strcmp(substr($haystack, 0, strlen($needle)),$needle)===0);}
    return (strcasecmp(substr($haystack, 0, strlen($needle)),$needle)===0);
}

function endsWith($haystack,$needle,$case=true) {
    if($case){return (strcmp(substr($haystack, strlen($haystack) - strlen($needle)),$needle)===0);}
    return (strcasecmp(substr($haystack, strlen($haystack) - strlen($needle)),$needle)===0);
}

Credit to:

• http://snipplr.com/view/13213/check-if-a-string-ends-with-another-string/
• http://snipplr.com/view/13214/check-if-a-string-begins-with-another-string/

Answer 2

Your best bet would be to use regular expressions and your functions would look something like this...

function startsWith($needle, $haystack)
{
   return preg_match('^'.$needle, $haystack);
}

function endsWith($needle, $haystack)
{
   return preg_match($needle .'$', $haystack);
}

Answer 3

function startsWith($string, $char)
{
    $length = strlen($char);
    return (substr($string, 0, $length) === $char);
}

function endsWith($string, $char)
{
    $length = strlen($char);
    $start =  $length *-1; //negative
    return (substr($string, $start, $length) === $char);
}

Use this if you don't want to use a regex.

Answer 4

All answers above seem to do loads of unnecessary work, strlen calculations, string allocations (substr) etc. The 'strpos' and 'stripos' functions return the index of the first occurrence of $needle in $haystack

function startsWith($haystack,$needle,$case=true)
{
   if($case)
       return strpos($haystack, $needle, 0) === 0;

   return stripos($haystack, $needle, 0) === 0;
}

function endsWith($haystack,$needle,$case=true)
{
  $expectedPosition = strlen($haystack) - strlen($needle);

  if($case)
      return strrpos($haystack, $needle, 0) === $expectedPosition;

  return strripos($haystack, $needle, 0) === $expectedPosition;
}

Answer 5

The regex functions above, but with the other tweaks also suggested above:

 function startsWith($needle, $haystack) 
 {
     return preg_match('/^'.preg_quote($needle)."/", $haystack);
 }

 function endsWith($needle, $haystack) 
 {
     return preg_match("/".preg_quote($needle) .'$/', $haystack);
 }

Answer 6

I realize this has been finished, but you may want to look at strncmp as it allows you to put the length of the string to compare against, so:

function startsWith($haystack, $needle, $case=true) {
    if ($case)
        return strncasecmp($haystack, $needle, strlen($needle)) == 0;
    else
        return strncmp($haystack, $needle, strlen($needle)) == 0;
}

Answer 7

Based on James Black's answer, here is its endsWith version:

function startsWith($haystack, $needle, $case=true) {
    if ($case)
        return strncmp($haystack, $needle, strlen($needle)) == 0;
    else
        return strncasecmp($haystack, $needle, strlen($needle)) == 0;
}

function endsWith($haystack, $needle, $case=true) {
     return startsWith(strrev($haystack),strrev($needle),$case);

}

Note: I have swapped the if-else part for James Black's startsWith function, because strncasecmp is actually the case-insensitive version of strncmp.

Answer 8

If speed is important for you, try this.(I believe it is the fastest method)

Works only for strings and if $haystack is only 1 character

function startsWithChar($needle, $haystack)
{
   return ($needle[0] === $haystack);
}

function endsWithChar($needle, $haystack)
{
   return ($needle[strlen($needle) - 1] === $haystack);
}

$str='|apples}';
echo startsWithChar($str,'|'); //Returns true
echo endsWithChar($str,'}'); //Returns true
echo startsWithChar($str,'='); //Returns false
echo endsWithChar($str,'#'); //Returns false

Answer 9

Here's just a fix on Sander Rijken's method. The $expectedPosition calculation is slightly off in endsWith. (The last -1 is not necessary).

    function startsWith($string, $prefix, $caseSensitive = true) {
    if(!$caseSensitive) {
        return stripos($string, $prefix, 0) === 0;
    }
    return strpos($string, $prefix, 0) === 0;
}

function endsWith($string, $postfix, $caseSensitive = true) {
    $expectedPostition = strlen($string) - strlen($postfix);

    if(!$caseSensitive) {
        return strripos($string, $postfix, 0) === $expectedPostition;
    }
    return strrpos($string, $postfix, 0) === $expectedPostition;
}

Answer 10

My personal preference would be eliminating all code repeats, so here is another version of Sander Rijken's method:

function contains($haystack, $needle, $case = true, $pos = 0)
{
    if ($case)
    {
        $result = (strpos($haystack, $needle, 0) === $pos);
    }
    else
    {
        $result = (stripos($haystack, $needle, 0) === $pos);
    }

    return $result;
}

function starts_with($haystack, $needle, $case = true)
{
    return contains($haystack, $needle, $case, 0);
}

function ends_with($haystack, $needle, $case = true)
{
    return contains($haystack, $needle, $case, (strlen($haystack) - strlen($needle)));
}