PHP error quotes using variable _php tips

When you see the error prompt
Syntax error, unexpected t_encapsed_and_whitespace, expecting t_string or t_variable or t_num_string
This hint is a question that prompts the variable to use it.
And what I'm showing is that the array was used in the statement, causing the failure. Below look at the failed code;
<?php
echo "I am an array, $n [' X ']";
?>
In this way, instant double quotes can parse variables, but in the case of a group like this, there is no way to parse the wording. Change it to the bottom!
<?php
echo "I am an array, {$n [' x ']}";
?>
Add curly braces {} to let the statement recognize that the inside is dynamic.