PHP foreach循环

foreach循环用于遍历数组元素。它只适用于数组和对象。如果尝试将其用于不同数据类型的变量，将会出现错误。

foreach循环根据元素而不是索引进行工作。它提供了一种最简单的方法来迭代数组的元素。

在foreach循环中，我们不需要递增值。

语法

foreach (array asvalue) {
    //code to be executed
}

还有一种foreach循环的语法。

语法

foreach (array askey => $element) { 
    //code to be executed
}

流程图

示例1

使用foreach循环打印数组元素的PHP程序。

<?php
    //declare array
    season = array ("Summer", "Winter", "Autumn", "Rainy");

    //access array elements using foreach loop
    foreach (season as element) {
        echo "element";
        echo "</br>";
    }
?>

输出：

Summer 
Winter 
Autumn 
Rainy

示例2

使用foreach循环打印关联数组元素的PHP程序。

<?php
    //declare array
    employee = array (
        "Name" => "Alex",
        "Email" => "alex_jtp@gmail.com",
        "Age" => 21,
        "Gender" => "Male"
    );

    //display associative array element through foreach loop
    foreach (employee as key =>element) {
        echo key . " : " .element;
        echo "</br>";   
    }
?>

输出：

Name : Alex
Email : stash
Age : 21
Gender : Male

示例3

多维数组

<?php
    //declare multi-dimensional array
    a = array();a[0][0] = "Alex";
    a[0][1] = "Bob";a[1][0] = "Camila";
    a[1][1] = "Denial";

    //display multi-dimensional array elements through foreach loop
    foreach (a as e1) {
        foreach (e1 as e2) {
            echo "e2\n";
        }
    }
?>

输出：

Alex Bob Camila Denial

示例4

动态数组

<?php
    //dynamic array
    foreach (array ('j', 'a', 'v', 'a', 't', 'p', 'o', 'i', 'n', 't') as elements) {
        echo "elements\n";
    }
?>

输出:

j a v a t p o i n t