php - add string at offset?

Question

If I have a string like \"test\", I have characters from offset 0-3. I would like to add another string to this one at offset 6. Is there a simple PHP function that can do this?

Answer 1

Convert the string to an array, in the case where the offset is greater than the string length fill in the missing indexes with a padding character of your choice otherwise just insert the string at the corresponding array index position and implode the string array.

Please see the function below:

function addStrAtOffset($origStr,$insertStr,$offset,$paddingCha=' ')
{
    $origStrArr = str_split($origStr,1);

    if ($offset >= count($origStrArr))
    {
        for ($i = count($origStrArr) ; $i <= $offset ; $i++)
        {
            if ($i == $offset) $origStrArr[] = $insertStr;
            else $origStrArr[] = $paddingCha;
        }
    }
    else
    {
        $origStrArr[$offset] = $insertStr.$origStrArr[$offset];
    }

    return implode($origStrArr);
}

echo addStrAtOffset('test','new',6);

Answer 2

To solve your problem first of all you convert your strings in arrays with str_split, then when you've got the array you're done, you can perform any kind of operations on these strings.

Code:

$s1 = "test";
$s2 = "new";
//converting string into array
$strings[0] = str_split($s1, 1);
$strings[1] = str_split($s2, 1);
//setting the first word of sentence
$sentence = $strings[0];
//insert every character in the sentence of "new" word
for ($i=0; $i < count($strings[1]); $i++) { 
    $sentence[] = $strings[1][$i];
}
print_r($sentence);

Result:

Array
(
    [0] => t
    [1] => e
    [2] => s
    [3] => t
    [4] => n
    [5] => e
    [6] => w
)