Application Analysis of PHP short-circuit operator

/** * PHP Short-circuit operator * Edit by Bbs.it-home.org */ mysql_query ($sql) or Die (' Execute failed! '); !file_exists ($cache _file) && @update_cache ($id); File_exists ($CWD. " /download/". $down _id) | | mkdir ($CWD. " /download/". $down _id,0757) ?> Copy Code Description: 1,[or [| |] [And] [&&] are short-circuit operators 2,or,| | The operator checks whether the first expression returns "true" and if "true" the closing sentence returns "true", otherwise the next expression is checked. The 3,and,&& operator checks whether the first expression returns "false", and if it is "false" the closing sentence returns "false", otherwise the second expression is checked. The above uses the characteristic of the short-circuit operator, realizes the condition judgment and the execution.

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