How to determine whether an array has content in php

PHP is a scripting language widely used in web development. It natively supports arrays and can easily store and manipulate data. In practical applications, we often need to determine whether an array is empty. This article will introduce how to determine whether an array has content in PHP.

1. Use the count() function

PHP provides the count() function, which can be used to count the number of elements in an array. Therefore, we can determine whether the array has content by determining whether the number of array elements is greater than 0. The following is a sample code:

$arr = [1, 2, 3];
if (count($arr) > 0) {
    echo '数组不为空';
} else {
    echo '数组为空';
}

In the above code, the count() function is used to count the number of array elements. If it is greater than 0, it outputs "the array is not empty", otherwise it outputs "the array is empty".

2. Use the empty() function

In addition to the count() function, PHP also provides the empty() function, which can determine whether a variable is empty, including empty strings, 0, and arrays Empty etc. Therefore, we can directly use the empty() function to determine whether the array is empty. The following is a sample code:

$arr = [];
if (empty($arr)) {
    echo '数组为空';
} else {
    echo '数组不为空';
}

In the above code, an empty array is assigned to the variable $arr, and then the empty() function is used to determine whether it is empty. If it is empty, "array is empty" is output, otherwise Output "array is not empty".

3. Use the array_filter() function

In addition to the above two methods, you can also use the PHP built-in function array_filter() to determine whether the array has content. The array_filter() function can be used to filter elements in an array that do not meet the conditions and return a new filtered array. If no elements in the original array meet the conditions, an empty array is returned, so we can use the array_filter() function to determine whether the array has content. The following is a sample code:

$arr = [1, 2, 3];
if (empty(array_filter($arr))) {
    echo '数组为空';
} else {
    echo '数组不为空';
}

In the above code, the array_filter() function is used to filter the elements in the array. If the filtered array is empty, then "array is empty" is output, otherwise "array is not empty" is output. ".

Summary

This article introduces three PHP methods to determine whether an array has content, namely using the count() function, empty() function and array_filter() function. Among them, the count() function can count the number of array elements, the empty() function can determine whether a variable is empty, and the array_filter() function can filter elements in the array that do not meet the conditions. Readers can choose a method that suits them according to the actual situation to determine whether the array has content.

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