How to obtain random numbers of four letters and numbers in php

How to obtain random numbers of four letters and numbers in php

This article mainly introduces some four-digit verification codes on the login interface or comment interface during php program development. For more information, see

 

 

So we know that in php, a simple four-digit pure digit verification can be done with rand (,), but if we want to get a random four-digit number of letters and numbers, so how do we write functions? The following Hu Peng blog provides a complete example in the php Document section.

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<? Php Function GetfourStr ($ len) { $ Chars_array = array ( "0", "1", "2", "3", "4", "5", "6", "7", "8", "9 ", "A", "B", "c", "d", "e", "f", "g", "h", "I", "j ", "k ", "L", "m", "n", "o", "p", "q", "r", "s", "t", "u ", "v ", "W", "x", "y", "z", "A", "B", "C", "D", "E", "F ", "G ", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q ", "R ", "S", "T", "U", "V", "W", "X", "Y", "Z ", ); $ CharsLen = count ($ chars_array)-1;   $ Outputstr = ""; For ($ I = 0; $ I <$ len; $ I ++) { $ Outputstr. = $ chars_array [mt_rand (0, $ charsLen)]; } Return $ outputstr; } Echo GetfourStr (4 ); ?>

Some Function parsing: mt_rand Function Description: mt_rand () returns a random integer.
If the optional parameters min and max are not provided, mt_rand () returns a pseudo-random number between 0 and RAND_MAX. For example, if you want a random number between 0 and 46 (including 0 and 46), use mt_rand (0, 46 ).