如何将字符串拆分为数组，而是链接新元素而不是在PHP中为每个分隔符添加元素？

I know how to do that with a loop obviously, but I wonder if there was a one line for turning this:

a/b/c/d

into

[a, a/b, a/b/c, a/b/c/d]

Not a one-liner exactly, but you can do this with array_reduce:

$arr = array_reduce(explode('/', 'a/b/c/d'), function($accumulator, $char) {
    $prev = empty($accumulator) ? '' : $accumulator[count($accumulator)-1] . '/';
    $accumulator[] = $prev.$char;
    return $accumulator;
}, []);

has a semi-colon in the closure, so I guess it's technically a two-liner

echo json_encode(array_map(function($val,&$accumulator){return $accumulator=$accumulator.$val; },explode('/','a/b/c/d'),array()));

Results in this:

["a","ab","abc","abcd"]