PHP user Custom Function variable parameter usage examples

php in the userCustom functions A variable number of parameter lists are supported in the

In php5.5 and earlier versions, the Func_num_args (), Func_get_arg ( ), and Func_get_args () functions were implemented.

<?phpfunction MyFunc () {  //Get the number of parameters  echo Func_num_args (). Php_eol;  Gets the value of the first parameter:  print_r (func_get_arg (0));  echo Php_eol;  Gets the value of all parameters  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 versions php5.6 and above, you can use ... Syntax implementation.

Example 1: Using the ... $args instead of any number of parameters

<?phpfunction myfunc (... $args) {  //Get the number of parameters  echo count ($args). Php_eol;  Gets the value of the first parameter:  print_r ($args [0]);  echo Php_eol;  Gets the value of all parameters  Print_r ($args);  echo Php_eol;} MyFunc (' a '); MyFunc (1, 2, 3); MyFunc (Array (' d ', ' e '), array (' F '));? >

The output is consistent with php5.5 using Func_num_args (), Func_get_arg (), and the Func_get_args () function.

Example 2: Array to parameter list

<?phpfunction Add ($a, $b) {  echo $a + $b;} $args = Array (1, 2); Add (... $args); Output 3?>

Example 3: Partial parameter designation, variable number of other parameters

<?phpfunction 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 ');d isplay (' Terry ', ' Designer ', 1, 2);d isplay (' Aoao ', ' tester ', Array (' A ', ' B '), Array ( ' C '), Array (' d '));? >

Output:

Name:fdipzonetag:programmerargs:Array () name:terrytag:designerargs:Array (  [0] = 1  [1] = 2) Name: Aoaotag:testerargs:Array (  [0] = = Array    (      [0] = a      [1] = b    )  [1] = = Array    (      [0] = c    )  [2] = = Array    (      [0] = d    ))