How to get the number of elements in an array in php

Array is a very important data type in PHP. It can store any type of data and supports fast traversal and operation of data. In PHP, you can use a variety of methods to get the elements in an array, including using subscripts, traversing the array, and using built-in functions. When getting an array element that also contains an array, you need to use multiple techniques and methods.

This article will introduce how to obtain the array of elements in an array in PHP, and provide some practical examples.

Method 1: Use multi-dimensional array subscripts

If the array elements also contain other arrays, you can use multi-dimensional array subscripts to obtain them. The format of a multidimensional array subscript is arrayindex1, where index1 and index2 are both integers or strings, representing the subscripts of the first and second dimension arrays.

The following is an example that demonstrates how to use the subscript of a multi-dimensional array to obtain the array in the array element:

<?php
//定义一个包含数组元素的数组
$students = array(
    array(&#39;name&#39; => 'Tom', 'age' => 18, 'score' => 90),
    array('name' => 'Jerry', 'age' => 20, 'score' => 85),
    array('name' => 'Mike', 'age' => 22, 'score' => 80),
);

//获取数组元素中的数组
$student = $students[0]; //获取第一个学生的信息
$score = $student['score']; //获取该学生的分数

//输出结果
echo "Tom的分数是：" . $score;
?>

In the above example, an array containing 3 student information is first defined $students. Then get the first student's information through $student = $students[0], and then get the student's score through $score = $student['score']. The final output result shows that Tom's score is: 90.

Method 2: Use multiple foreach loops

If an array element contains multiple arrays, you can use multiple foreach loops to obtain each of the array elements.

The following is an example that demonstrates how to use multiple foreach loops to obtain the array elements in the array:

<?php
//定义一个包含数组元素的数组
$students = array(
    array(&#39;name&#39; => 'Tom', 'age' => 18, 'score' => array(90, 80, 95)),
    array('name' => 'Jerry', 'age' => 20, 'score' => array(85, 90, 80)),
    array('name' => 'Mike', 'age' => 22, 'score' => array(80, 85, 75)),
);

//获取数组元素中的数组
foreach($students as $student){
    //遍历每个学生的信息
    echo $student['name'] . '的分数是：';
    foreach($student['score'] as $score){
        //遍历该学生的分数
        echo $score . ',';
    }
    echo '<br/>';
}
?>

In the above example, an array $students containing 3 student information is first defined. . Then use multiple foreach loops to iterate through each student in the array, then traverse the student's scores, and finally output the results.

Method 3: Use the array_column function

If an array element contains multiple arrays, you can use the array_column function to get all the values ​​of one of the array elements. The syntax of the array_column function is array_column(array,column_key,index_key), where array represents the array to be processed, column_key represents the key name of the array element to be obtained, and index_key represents the field used as the key name of the returned array.

The following is an example that demonstrates how to use the array_column function to obtain an array in an array element:

<?php
//定义一个包含数组元素的数组
$students = array(
    array(&#39;name&#39; => 'Tom', 'age' => 18, 'score' => array(90, 80, 95)),
    array('name' => 'Jerry', 'age' => 20, 'score' => array(85, 90, 80)),
    array('name' => 'Mike', 'age' => 22, 'score' => array(80, 85, 75)),
);

//获取数组元素中的数组
$scores = array_column($students, 'score');

//输出结果
print_r($scores);
?>

In the above example, an array $students containing 3 student information is first defined. Then use the array_column function to get the score of each student, that is, $scores = array_column($students, 'score'). The final output result is the score of each student.

Conclusion

In PHP, you can use a variety of methods to obtain the array in the array element, including using multi-dimensional array subscripts, multiple foreach loops, and the array_column function. Different methods are suitable for different scenarios, and the appropriate method needs to be selected according to the specific situation.

The above is the detailed content of How to get the number of elements in an array in php. For more information, please follow other related articles on the PHP Chinese website!