Remove the last character from a string

What is fastest way to remove the last character from a string?

I have a string like

a,b,c,d,e,

I would like to remove the last ',' and get the remaining string back:

OUTPUT: a,b,c,d,e

What is the fastest way to do this?

First, I try without a space, rtrim($arraynama, ","); and get an error result.

Then I add a space and get a good result:

$newarraynama = rtrim($arraynama, ", ");

You can use substr:

echo substr('a,b,c,d,e,', 0, -1);
# => 'a,b,c,d,e'

An alternative to substr is the following, as a function:

substr_replace($string, "", -1)

Is it the fastest? I don't know, but I'm willing to bet these alternatives are all so fast that it just doesn't matter.

You can use

substr(string $string, int $start, int[optional] $length=null);

See substr in the PHP documentation. It returns part of a string.

"The fastest best code is the code that doesn't exist".

Speaking of edge cases, there is a quite common issue with the trailing comma that appears after the loop, like

$str = '';
foreach ($array as $value) {
    $str .= "$value,";
}

which, I suppose, also could be the case in the initial question. In this case, the fastest method definitely would be not to add the trailing comma at all:

$str = '';
foreach ($array as $value) {
    $str .= $str ? "," : "";
    $str .= $value;
}

here we are checking whether $str has any value already, and if so - adding a comma before the next item, thus having no extra commas in the result.