array_keys_PHP array_keys（）函数与示例

我就是我 2023-03-05 13:26 15阅读 0赞

array\_keys

## PHP array\_keys()函数 **(**PHP array\_keys() function**)** ##

**array\_keys() function** is used to get the keys of an array, it accepts an array as an argument and returns a new array containing keys.

**array\_keys()函数**用于获取数组的键，它接受一个数组作为参数并返回一个包含键的新数组。

**Syntax:**

**句法：**

array_keys(input_array, [value], [strict]);

Here,

这里，

*  input\_array is an array (i.e. input array).
    
    input\_array是一个数组(即输入数组)。
 *  value is an optional parameter, it is used to define a value if the value is defined, then the only keys having that value are returned.
    
    value是一个可选参数，如果定义了值，则用于定义值，然后仅返回具有该值的键。
 *  strict is also an optional parameter, it is default set to false if we set it true the type of values will be checked.
    
    严格也是一个可选的参数，它是默认设置为false，如果我们把它真值的类型将被检查。

**Examples:**

**例子：**

Input:
        $per = array("name" => "Amit", "age" => 21, "gender" => "Male");
       
        Output:
        Array       
        (
            [0] => name    
            [1] => age     
            [2] => gender  
        )

**PHP code 1: array with and without containing keys**

**PHP代码1：包含和不包含键的数组**

<?php
        $per = array("name" => "Amit", "age" => 21, "gender" => "Male");
        print ("keys array...\n");
        print_r (array_keys($per));
        
        //array with out keys 
        $arr = array("Hello", "world", 100, 200, -10);
        print ("keys array...\n");
        print_r (array_keys($arr));    
    ?>

**Output**

**输出量**

keys array...      
    Array       
    (
        [0] => name    
        [1] => age     
        [2] => gender  
    )
    keys array...      
    Array       
    (
        [0] => 0
        [1] => 1
        [2] => 2
        [3] => 3
        [4] => 4
    )

**PHP code 2: Using value and strict mode**

**PHP代码2：使用值和严格模式**

<?php
        $arr = array("101" => 100, "102" => "100", "103" => 200);
        
        print("output (default function call)...\n");
        print_r (array_keys($arr));    
    
        print("output (with checking value)...\n");
        print_r (array_keys($arr, 100));        
    
        print("output (with checking value & strict mode)...\n");
        print_r (array_keys($arr, 100, true));            
        
    ?>

**Output**

**输出量**

output (default function call)...
    Array         
    (             
        [0] => 101
        [1] => 102
        [2] => 103
    )             
    output (with checking value)...  
    Array         
    (             
        [0] => 101
        [1] => 102
    )             
    output (with checking value & strict mode)...
    Array         
    (             
        [0] => 101
    )

> 翻译自: [https://www.includehelp.com/php/array\_keys-function-with-example.aspx][https_www.includehelp.com_php_array_keys-function-with-example.aspx]

array\_keys

[https_www.includehelp.com_php_array_keys-function-with-example.aspx]: https://www.includehelp.com/php/array_keys-function-with-example.aspx