How to filter meta-characters contained in input content with PHP

How to filter the meta-characters contained in the input content with PHP
How to filter the meta-characters contained in the input content with PHP

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What metacharacters need to be filtered using \ To resolve such as '/\?+/', $str


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Batting practice is very good at this. Batting practice to help you.
Hero, what function do you want to achieve?

Regular expressions
()
Greed. *
Not greedy. *?
Safety U.
Case Sensitive I



Find with Preg_match (regular, target, result still an array)
Replacement with preg_replace (regular, target, source)

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