How to use filter_var() function in PHP? (code example)
In PHP, the filter_var() function will use the specified filter to filter variables; it can filter the data passed by the user. The following article will introduce to you the usage of filter_var() function. I hope it will be helpful to you. [Video tutorial recommendation: PHP tutorial]
##PHP filter_var() function
Basic syntax
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Parameters: filter_var() function accepts three parameters
●var: indicates what to filter Variable, cannot be omitted (required parameter). ● filtername: used to specify the ID or name of the filter to be used. The default value is FILTER_DEFAULT, which causes no filtering; can be omitted. ● Options: Used to specify one or more flags/options to be used. Checks each filter for possible options and flags; may be omitted.Return value: If the filtering is successful, the filtered data will be returned; if the filtering fails, FALSE will be returned.
Usage example of PHP filter_var() function
Example 1: Filter string
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Description: FILTER_SANITIZE_NUMBER_INT means to delete all other characters except numbers and -.
Example 2: Verify IP address
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Example 3: Filter and verify email (email) addresses
The filter_var() function first starts from Remove all illegal characters from the variable containing the email address and then check if it is a valid email address:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
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Example 4: Filter and verify URL
filter_var() function first removes all illegal characters from the URL and then checks if it is a valid URL:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
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