PHP array Array_filter () function and array_slice () function

/*

Array_filter () filters cells in an array with a callback function

Array_filter (array,function)

Parameter description: If the custom filter function returns True, the current value of the array being manipulated is included in the returned result array.

And make a new array of results, if the original array is an associative array, the key name remains unchanged.

*/

function Delempty ($val) {

if ($val = = = "" | | $val = = = "php") {//when null and PHP values are present in the array, return false, that is, remove null values and PHP values from the array

return false;

}

return true;

}

$input _array = Array (' A ' = = ' Java ',

' B ' =>false,

' B1 ' =>true,

' C ' and ' = ',

' D ' and ' = ',

' E ' =>null,

' G ' =>0,

' G1 ' = ' 0 ',

' H ' = ' php ');

Print_r (Array_filter ($input _array));

Print_r (Array_filter ($input _array, "Delempty"));

?>

The result of running without a callback function:

As you can see, false,null, and the real ' blank ' and 0 are filtered, and the subscript of the array has not changed.

There is a result of the callback function running:

[PHP] view plaincopyprint?

/**

* the Array_slice () function takes a paragraph out of the array

* Array_slice (array array, int offset[, int length])

* A sequence of arrays in an array, as specified by the offset and length parameters.

* Offset indicates the start position, and length indicates how long the sequence is.

* True key does not change

*/

$input = Array ("Java", "Php",

"C + +", "C #",

"Ruby", "object-c");

$outputA = Array_slice ($input, 2); Returns "C + +", "C #", "Ruby", "Object-c"

$outputB = Array_slice ($input,-2, 1); Returns "Ruby"

$outputC = Array_slice ($input, 1, 3); Returns "PHP", "C + +", "C #"

Print_r ($outputA);

Print_r ($outputB);

Print_r ($outputC);

Print_r (Array_slice ($input, 2,-1, true));

Print_r (Array_slice ($input, 2,-1));

?>

Operation Result:

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