PHP Ds\Map count()用法及代码示例

Ds \ Map::count()函数是PHP中的一个内置函数，用于计算Map中存在的元素数。它也指Map的大小。

用法:

int public Ds\Map::count()

参数：该函数不接受任何参数。

返回值：此函数返回Map中存在的元素数。

以下示例程序旨在说明PHP中的Ds \ Map::count()函数：

程序1:

<?php  
// PHP program to illustrate the count()  
// function of Ds\map  
  
// Creating a Map  
$map = new \Ds\Map([ 
    "1" => "Geeks",   
    "2" => "for", 
    "3" => "Geeks"
]);  
  
// Display the map elements 
print_r($map);  
  
echo "Number of elements present in map:"; 
print_r($map->count()); 
  
?>

输出：

Ds\Map Object
(
    [0] => Ds\Pair Object
        (
            [key] => 1
            [value] => Geeks
        )

    [1] => Ds\Pair Object
        (
            [key] => 2
            [value] => for
        )

    [2] => Ds\Pair Object
        (
            [key] => 3
            [value] => Geeks
        )

)
Number of elements present in map:3

程序2:

<?php  
// PHP program to illustrate the count()  
// function of Ds\map  
  
// Creating a Map  
$map = new \Ds\Map(["1" => "10",  
            "2" => "20", "3" => 30, "4" => 40]);  
  
// Print map elements 
print_r($map);  
  
echo "Number of elements present in map:"; 
print_r($map->count()); 
  
echo "\n"; 
  
// Creating another Map  
$map = new \Ds\Map([1 => "Welcome",  
            2 => "to", 3 => "GeeksforGeeks"]);  
  
// Print map elements 
print_r($map);  
  
echo "Number of elements present in map:"; 
print_r($map->count()); 
  
?>

输出：

Ds\Map Object
(
    [0] => Ds\Pair Object
        (
            [key] => 1
            [value] => 10
        )

    [1] => Ds\Pair Object
        (
            [key] => 2
            [value] => 20
        )

    [2] => Ds\Pair Object
        (
            [key] => 3
            [value] => 30
        )

    [3] => Ds\Pair Object
        (
            [key] => 4
            [value] => 40
        )

)
Number of elements present in map:4
Ds\Map Object
(
    [0] => Ds\Pair Object
        (
            [key] => 1
            [value] => Welcome
        )

    [1] => Ds\Pair Object
        (
            [key] => 2
            [value] => to
        )

    [2] => Ds\Pair Object
        (
            [key] => 3
            [value] => GeeksforGeeks
        )

)
Number of elements present in map:3

参考： https://www.php.net/manual/en/ds-map.count.php

相关用法

注：本文由纯净天空筛选整理自jit_t大神的英文原创作品 PHP | Ds\Map count() Function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。