How to use array_keys function in php

Usage of array_keys function in php: [array_keys(array,value,strict)]. The array_keys function is used to return a new array containing all the keys in the array.

php The array_keys function returns a new array containing all the key names in the array. Its syntax is array_keys(array,value,strict). The parameter array is required and refers to Specifies an array.

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How to use the php array_keys function?

Function: Return the contained array A new array of all key names.

Syntax:

array_keys(array,value,strict)

Parameters:

array Required. Specifies an array.

value Optional. You can specify a key value, and then only the key name corresponding to that key value will be returned.​

strict Optional. Used with the value parameter. Possible values: true - Returns the key name with the specified key value. Depending on the type, the number 5 is not the same as the string "5". false - the default value. Independent of type, the number 5 is the same as the string "5".

Description:

Returns a new array containing all the key names in the array. If the second argument is provided, only the key names whose key value is this value are returned. If the strict parameter is specified as true, PHP uses equality comparison (===) to strictly check the data type of the key value.

php array_keys() function usage example 1

<?php
$a = array("class" => "php中文网","name" => "西门","job" => "讲师");
print_r(array_keys($a));
?>

Output:

Array ( [0] => class [1] => name [2] => job )

php array_keys() function usage example 2

<?php
$a = array("class" => "php中文网","name" => "无忌哥哥","job" => "考官");
print_r(array_keys($a));
?>

Output:

Array ( [0] => class [1] => name [2] => job )

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