How to find the number of array elements in php

In PHP, there are many ways to obtain the number of array elements. This article will introduce these methods respectively so that readers can use them flexibly in actual development.

Method 1: count function

The count function in PHP can be used to count the number of array elements. When the array is empty, the function returns 0. When there are elements in the array, this function returns the number of elements.

The following is an example of using the count function to count the number of array elements:

$num_array = array(10,20,30,40,50);
echo count($num_array);

The output result is: 5

Method 2: sizeof function

In addition to count Function, PHP also provides a similar function - the sizeof function, which can also count the number of array elements. The functions of the sizeof function and the count function are basically the same, but they are slightly different in some aspects of their application.

The following is an example of using the sizeof function to count the number of array elements:

$num_array = array(10,20,30,40,50);
echo sizeof($num_array);

The output result is: 5

Method 3: Traverse the array

In PHP , we can also find the number of array elements by traversing the array. The idea of ​​this method is to traverse each element in the array in turn and use a loop counter to save the number of elements.

The following is an example of counting the number of elements by traversing the array:

$num_array = array(10,20,30,40,50);
$count = 0;
foreach($num_array as $num){
    $count ++;
}
echo $count;

The output result is: 5

Method 4: array_sum function

In addition to the above In this way, we can also use the array_sum function to find the number of array elements. The basic idea of ​​this function is to add up all the elements in the array to obtain the number of elements.

The following is an example of using the array_sum function to count the number of elements:

$num_array = array(10,20,30,40,50);
echo array_sum($num_array);

The output result is: 150

Since each array is an object, when creating, We can add the number attribute of the array elements to the array, so that we can directly reference this attribute when getting the number of array elements. This method can improve the efficiency of the code, but because it requires modifying the definition of the array, the scope of application will be limited.

To sum up, we can see that PHP provides a variety of ways to find the number of array elements, and developers should choose according to the actual situation.

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