PHP function to verify whether credit card number is correct_PHP tutorial

PHP function to verify whether the credit card number is correct

This article mainly introduces the PHP function to verify whether the credit card number is correct. This article directly gives the implementation code. Friends who need it can refer to it

You can use the following PHP function to verify whether a card number is a credit card:

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function validateCard ( $cardnumber ) { $cardnumber = preg_replace ( " /D|s/ " , "" , $cardnumber ) ; # strip any non-digits $cardlength = strlen ( $cardnumber ) ; if ( $cardlength != 0 ) { $parity = $cardlength % 2 ; $sum = 0 ; for ( $i = 0 ; $i < $cardlength ; $i ) { $digit = $cardnumber [ $i ] ; if ( $i % 2 == $parity ) $digit = $digit * 2 ; if ( $digit > 9 ) $digit = $digit - 9 ; $sum = $sum $digit ; } $valid = ( $sum % 10 == 0 ) ; return $valid ; } return false ; }

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function validateCard ( $cardnumber ) { $cardnumber = preg_replace ( " /D|s/ " , "" , $cardnumber ) ; # strip any non-digits $cardlength = strlen ( $cardnumber ) ; if ( $cardlength != 0 ) { $parity = $cardlength % 2 ; $sum = 0 ; for ( $i = 0 ; $i < $cardlength ; $i )<🎜> <🎜>{<🎜> <🎜>$digit = $cardnumber [ $i ] ;<🎜> <🎜>if ( $i % 2 == $parity ) $digit = $digit * 2 ;<🎜> <🎜>if ( $digit > 9 ) $digit = $digit - 9 ; $sum = $sum $digit ; } $valid = ( $sum % 10 == 0 ) ; return $valid ; } return false ; }

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