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php supports variable number of parameter lists in user-defined functions.
In php5.5 and earlier versions, use the func_num_args(), func_get_arg(), func_get_args() function implementation.
<?php function myfunc(){ // 获取参数数量 echo func_num_args().PHP_EOL; // 获取第一个参数的值: print_r(func_get_arg(0)); echo PHP_EOL; // 获取所有参数的值 print_r(func_get_args()); echo PHP_EOL; } myfunc('a'); myfunc(1, 2, 3); myfunc(array('d','e'), array('f'));?>
Output:
1aArray( [0] => a )31Array( [0] => 1 [1] => 2 [2] => 3)2Array( [0] => d [1] => e )Array( [0] => Array ( [0] => d [1] => e ) [1] => Array ( [0] => f ) )
In php5.6 and above, This can be achieved using the … syntax.
Example 1: Use...$args to replace any number of parameters
<?php function myfunc(...$args){ // 获取参数数量 echo count($args).PHP_EOL; // 获取第一个参数的值: print_r($args[0]); echo PHP_EOL; // 获取所有参数的值 print_r($args); echo PHP_EOL; } myfunc('a'); myfunc(1, 2, 3); myfunc(array('d','e'), array('f'));?>
The output results are the same as php5.5 using func_num_args(), func_get_arg() , the func_get_args() function is consistent.
Example 2: Convert array to parameter list
<?php function add($a, $b){ echo $a + $b; }$args = array(1, 2); add(...$args); // 输出3?>
Example 3: Some parameters are specified, and the number of other parameters is variable
<?php function display($name, $tag, ...$args){ echo 'name:'.$name.PHP_EOL; echo 'tag:'.$tag.PHP_EOL; echo 'args:'.PHP_EOL; print_r($args); echo PHP_EOL; } display('fdipzone', 'programmer'); display('terry', 'designer', 1, 2); display('aoao', 'tester', array('a','b'), array('c'), array('d'));?>
Output:
name:fdipzone tag:programmer args:Array( ) name:terry tag:designer args:Array( [0] => 1 [1] => 2) name:aoao tag:tester args:Array( [0] => Array ( [0] => a [1] => b ) [1] => Array ( [0] => c ) [2] => Array ( [0] => d ) )
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