numbers

What is the best way to validate a credit card in PHP?

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There are three parts to the validation of the card number: PATTERN – does it match an issuers pattern (e.g. VISA/Mastercard/etc.) CHECKSUM – does it actually check-sum (e.g. not just 13 random numbers after “34” to make it an AMEX card number) REALLY EXISTS – does it actually have an associated account (you are unlikely … Read more

How to convert Int to Hex String in Kotlin?

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You can still use the Java conversion by calling the static function on java.lang.Integer: val hexString = java.lang.Integer.toHexString(i) And, starting with Kotlin 1.1, there is a function in the Kotlin standard library that does the conversion, too: fun Int.toString(radix: Int): String Returns a string representation of this Int value in the specified radix. Note, however, … Read more

Formatting money in twig templates

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The number_format filter has been included in the Twig core since the end of December 2011. The relevant commit is here. Usage: number_format(decimals, decimalSeparator, thousandSeparator) {{ total|number_format(2) }} {{ total|number_format(0, ‘.’) }} {{ total|number_format(2, ‘.’, ‘,’) }} Read more about it in the docs

Print leading zeros with C++ output operator?

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This will do the trick, at least for non-negative numbers(a) such as the ZIP codes(b) mentioned in your question. #include <iostream> #include <iomanip> using namespace std; cout << setw(5) << setfill(‘0’) << zipCode << endl; // or use this if you don’t like ‘using namespace std;’ std::cout << std::setw(5) << std::setfill(‘0’) << zipCode << std::endl; … Read more