如何通过文本区域输入调用php中的预定义变量?就像预览时显示为表的｛table｝｛/table｝一样 - how to call predefined variable in php through textarea input? just like {table}{/table} shown as table when previewed

how to call predefined variable in php through textarea input? just like {table}{/table} shown as table when previewed

我是编程新手，我不知道使用这种预期编程的函数或方法。是这样的

PHP FILEPHP 上的预定义变量

<?php $a=1 ;$b=2;$c=3; $d=4; ?>

HTML FILE在文本区域输入在文本区域的顶部写入

使用代码{a}生成1，{b}生成2，{c}生成3，{d} 生成4个

所以当用户在下面输入时：

I wanna buy {a} apple, {b} mangos, {c} grapes and {d} oranges

OUTPUT在php上进行echo时，解析{代码}将被引用到预定义的变量

I wanna buy 1 apple, 2 mangos, 3 grapes and 4 oranges

有人可以帮我使用什么库或函数吗？感谢

也许一个简单的preg_replace_callback可以完成

<?php 
$values = array('a'=>1, 'b'=>2, 'c'=>3, 'd'=>4); // I don't want to litter the global namespace -> array
$userinput = 'I wanna buy {a} apple, {b} mangos, {c} grapes and {d} oranges';
$result = preg_replace_callback(
    '!{([a-z])}!', // limited to one small-case latin letter 
    function ($capture) use ($values) { 
        // for each match this function is called
        // use($values) "imports the array into the function
        // whatever this function returns replaces the match in the subject string
        $key = $capture[1];
        return isset($values[$key]) ? $values[$key] : '';
    },
    $userinput
);
echo $result;

打印

I wanna buy 1 apple, 2 mangos, 3 grapes and 4 oranges