How can I remove the last part of a string? - php

Question

This is my string:
monkey/rabbit/cat/donkey/duck
If my variable is cat...
$animal = cat
... I want to remove everything coming after cat.
My desired result is:
monkey/rabbit/cat
I tried to use str_replace:
$subject = 'monkey/rabbit/cat/donkey/duck';
$trimmed = str_replace($animal, '', $subject);
echo $trimmed;
But here I get the result:
monkey/rabbit//donkey/duck
So it is just cutting out cat.

Answer 1

You can combine strpos with substr:
$pos = strpos($subject, $animal);
if ($pos !== false) {
$result = substr($subject, 0, $pos + strlen($animal));
}
If you wold like to make sure it only the full segments are erased, in case of a partial match, you could use the offset argument of strpos:
$pos = strpos($subject, $animal);
if ($pos !== false) {
$result = substr($subject, 0, strpos($subject, '/', $pos));
}

Answer 2

You can use explode in your case:
$string = "monkey/rabbit/cat/donkey/duck";
$val = explode("donkey", $string );
echo $val[0];
Result: monkey/rabbit/cat
PS* Ofcourse there are better ways to do this

Answer 3

My approach would be to explode by your variable.
Take the first part and append the variable.
<?php
$string = 'monkey/rabbit/cat/donkey/duck';
$animal = 'cat';
$temp = explode($animal,$string);
print $temp[0] . $animal;
Will output nicely
monkey/rabbit/cat
There's no need to use any of strpos, strlen, substr or donkeys

Answer 4

<?php
$animal="cat";
$string1="monkey/rabbit/cat/donkey/duck";
$parts = explode($animal, $string1);
$res = $parts[0];
print("$res$animal")
?>

Answer 5

Here is a bit of explanation for what each step does:
$subject = 'monkey/rabbit/cat/donkey/duck';
$target = 'cat';
$target_length = strlen($target); // get the length of your target string
$target_index = strpos($subject, $target); // find the position of your target string
$new_length = $target_index + $target_length; // find the length of the new string
$new_subject = substr($subject, 0, $new_length); // trim to the new length using substr
echo $new_subject;
This can all be combined into one statement.
$new_subject = substr($subject, 0, strpos($subject, $target) + strlen($target));
This assumes your target is found. If the target is not found, the subject will be trimmed to the length of the target, which obviously is not what you want. For example, if your target string was "fish" the new subject would be "monk". This is why the other answer checks if ($pos !== false) {.
One of the comments on your question raises a valid point. If you search for a string that happens to be contained in one of the other strings, you may get unexpected results. There is really not a good way to avoid this problem when using the substr/strpos method. If you want to be sure to only match a complete word between your separators (/), you can explode by / and search for your target in the resulting array.
$subject = explode('/', $subject); // convert to array
$index = array_search($target, $subject); // find the target
if ($index !== false) { // if it is found,
$subject = array_slice($subject, 0, $index + 1); // remove the end of the array after it
}
$new_subject = implode('/', $subject); // convert back to string

Answer 6

I'm probably going to kop some flak for going down the RegExp route but...
$subject = 'monkey/rabbit/polecat/cat/catfish/duck';
$animal = "cat";
echo preg_replace('~(.*(?:/|^)' . preg_quote($animal) . ')(?:/|$).*~i', "$1", $subject);
This will ensure that your animal is wrapped immediately on either side with / characters, or that it's at the start or end of the string (i.e. monkey or duck).
So in this example it'll output:
monkey/rabbit/polecat/cat
Ending specifically with cat rather than stumbling at polecat or catfish