Efficient way to replace placeholders with variables [duplicate]

Answer 1

str_replace is not only ugly, but also sluggish if you need to replace ten variables (does a binary search and starts from the beginning for each alternative).

Rather use a preg_replace_callback, either listing all 10 variables at once, or using a late-lookup:

$src = preg_replace_callback('/\{\{(\w+)}}/', 'replace_vars', $src);
                     # or (NAME|THING|FOO|BAR|FIVE|SIX|SVN|EGT|NNE|TEN)

function replace_vars($match) {
    list ($_, $name) = $match;
    if (isset($this->vars[$name])) return $this->vars[$name];
}

Answer 2

What about strtr

$trans = array(
    '{{NAME}}' => $name, 
    "{{AGE}}"   => $age,
    ......
);
echo strtr($text, $trans);

Answer 3

What so ugly about str_replace()?

function replace_vars($string)
{
    $vars = array('NAME'=>'Name', 'VAR2'=>'Value 2', 'VAR3'=>'Value 3');

    $names = array();
    foreach($vars as $name=>$var) {
        $names[] = '{{'.$name.'}';
    }

    return str_replace($names, $vars, $string);
}

or

function replace_vars($string)
{
    $vars = array('{{NAME}}'=>'Name', '{{VAR2}}'=>'Value 2', '{{VAR3}}'=>'Value 3');

    return str_replace(array_keys($vars), $vars, $string);
}