PHP - iterate on string characters

2019-01-16 17:35发布

Is there a nice way to iterate on the characters of a string? I'd like to be able to do foreach, array_map, array_walk, array_filter etc. on the characters of a string.

Type casting/juggling didnt get me anywhere (put the whole string as one element of array), and the best solution I've found is simply using a for loop to construct the array. It feels like there should be something better. I mean, if you can index on it shouldn't you be able to iterate as well?

This is the best I've got

function stringToArray($s)
{
    $r = array();
    for($i=0; $i<strlen($s); $i++) 
         $r[$i] = $s[$i];
    return $r;
}

$s1 = "textasstringwoohoo";
$arr = stringToArray($s1); //$arr now has character array

$ascval = array_map('ord', $arr);  //so i can do stuff like this
$foreach ($arr as $curChar) {....}
$evenAsciiOnly = array_filter( function($x) {return ord($x) % 2 === 0;}, $arr);

Is there either:

A) A way to make the string iterable
B) A better way to build the character array from the string (and if so, how about the other direction?)

I feel like im missing something obvious here.

8条回答
贼婆χ
2楼-- · 2019-01-16 18:11

Hmm... There's no need to complicate things. The basics work great always.

    $string = 'abcdef';
    $len = strlen( $string );
    $x = 0;

Forward Direction:

while ( $len > $x ) echo $string[ $x++ ];

Outputs: abcdef

Reverse Direction:

while ( $len ) echo $string[ --$len ];

Outputs: fedcba

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走好不送
3楼-- · 2019-01-16 18:16

Expanded from @SeaBrightSystems answer, you could try this:

$s1 = "textasstringwoohoo";
$arr = str_split($s1); //$arr now has character array
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