字符串中的下标数字

Question

我想为字符串中的每个数字添加下标。

例如：

$str = '1Department of Chemistry, College of 2Education for Pure Science';

我想要的输出：

<sub>1</sub>Department of Chemistry, College of <sub>2<sub>Education for Pure Science

我从一个字符串中获取了所有数字：

//digits from string 
preg_match_all('!\d+!', $str, $matches);
print_r($matches);

但是我怎样才能对数字应用下标效果并打印字符串呢？

Answer 1

这可能有帮助：

$str = '1Department of Chemistry, College of 2Education for Pure Science';
preg_match_all('!\d+!', $str, $matches);
foreach($matches[0] as $no){
    $str = str_replace($no, '<sub>'.$no.'</sub>', $str);
}
echo htmlentities($str);

将给出输出：

<sub>1</sub>Department of Chemistry, College of <sub>2</sub>Education for Pure Science

或preg_replace将给出相同的输出：

$str = '1Department of Chemistry, College of 2Education for Pure Science';
$str = preg_replace( '!\d+!', '<sub>[=12=]</sub>', $str );
echo htmlentities($str);

Answer 2

您可以使用 preg_replace:

preg_replace( '!\d+!', '<sub>[=10=]</sub>', $str );

Demo

Answer 3

<?php

function subscript($string)
{
    return preg_replace('/(\d+)/', '<sub>\1</sub>', $string);
}

$input    = '1Department of Chemistry, College of 2Education for Pure Science';
$expected = '<sub>1</sub>Department of Chemistry, College of <sub>2</sub>Education for Pure Science';
$output   = subscript($input);

if ($output === $expected) {
    printf('It works! %s', htmlentities($output));
} else {
    printf('It does not work! %s', htmlentities($output));
}

Answer 4

我假设你想要这样的东西

$string = '1Department of Chemistry, College of 2Education for Pure Science';
$pattern = '/(\d+)/';
$replacement = '<sub></sub>';
echo preg_replace($pattern, $replacement, $string);

找到的号码将替换为子标签中的号码本身。该示例取自 PHP preg-replace 手册，您可以在此处找到 http://php.net/manual/en/function.preg-replace.php

Answer 5

我已经知道你已经接受了答案，但我仍然发布这个答案是因为我在处理它，其次这可能对将来的其他人有帮助。

<?php

$str = '1Department of Chemistry, College of 2Education for Pure Science';

$strlen = strlen( $str );
$numbers = array();
$replace = array();
for( $i = 0; $i <= $strlen; $i++ ) {
    $char = substr( $str, $i, 1 );
    // $char contains the current character, so do your processing here
    if(is_numeric($char)){
        $numbers[] = $char;
        $replace[] = "<sub>".$char."</sub>";
    }
}

echo $str = str_replace($numbers, $replace, $str);

?>

字符串中的下标数字

Subscript digits from a string

php

regex

subscript