A set of non-repeated number implementation programs are randomly generated in PHP.

The following describes how to randomly generate a set of non-repeated number implementation code in two PHP programs. For more information, see. The code is as follows: Copy the code? Php **...

The following describes how to randomly generate a set of non-repeated number implementation code in two PHP programs. For more information, see.

The code is as follows:

/** * PHP obtains a set of random numbers without duplicates. */ $ A = microtime (); Function createRandID ($ m ){ // Generate an array from 1 to $ m $ Arr = range (1, $ m ); // Disrupt the array Shuffle ($ arr ); // Obtain the first 10 For ($ I = 0; $ I <= 10; $ I ++ ){ // Assign a value to the new array $ n $ N [] = $ arr [$ I]; } // Return this set of numbers Return implode ($ n ,','); } Echo createRandID (700000 ); Echo' '; Echo $ a-microtime (); ?>

Execution result:

560875,593409, 325987,658308, 248054,205426, 375413,676243, 485853,575393, 115975
0.672761

The above results show that the time spent is 0.6. We can adjust the random number range from 700000 to 900000 and then check the execution result.

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 7200000 bytes) in/data0/htdocs/www/a. php on line 10

The array is too large to run !!

The code is as follows:

/** * PHP obtains a set of random numbers without duplicates. * Qiongtai blog */ $ A = microtime (); Function createRandID ($ m ){ // Note: you must declare an empty array first. Otherwise, the in_array in while will report an error. $ Arr = array (); // Use the while loop. if there are less than 10, the loop will always be done. While (count ($ arr) <= 10 ){ // Generate a random number $ A = rand (1, $ m ); // Judgment: If the generated random number is no longer in the array, it is assigned to the array. // Avoid repeated numbers If (! In_array ($ a, $ arr )){ // Assign a random number to an array $ Arr [] = $; } } // Return the generated random number Return implode ($ arr ,','); } Echo createRandID (700000 ); Echo' '; Echo $ a-microtime (); ?>

Execution result:

308326,155128, 280369,493174, 214855,219990, 482837,66329, 512934,232527, 386975
0.00015699999999996

We can see from the preceding execution results that the time is negligible. we can adjust the random number range from 700000 to 999999 to see the execution result.

392281,822956, 401282,176255, 143076,501802, 393338,546922, 21836,601991, 362006
0.00013600000000002

The execution result has nothing to do with the maximum value setting. it is still running fast!

Article URL:

Reprint ^ at will, but please attach the tutorial address.