How to determine the length of php array

PHP is a very popular programming language, and in PHP, arrays are a very important and commonly used data type. When we use PHP arrays, we may encounter situations where we need to determine the length of the array. This article will introduce several methods to determine the length of the PHP array.

Method 1: count function

PHP’s built-in function count() can return the number of elements in an array, so you can use this function to get the length of the array. The following is a sample code:

<?php //定义一个数组
$array = array(1, 2, 3, 4, 5);

//使用count函数来获取数组的长度
$length = count($array);

echo $length; //输出5
?>

Method 2: sizeof function

In addition to the count() function, you can also use the sizeof() function to obtain the length of the array. The functions of these two functions Similar, the methods used are basically the same. Here is the sample code:

<?php //定义一个数组
$array = array(1, 2, 3, 4, 5);

//使用sizeof函数来获取数组的长度
$length = sizeof($array);

echo $length; //输出5
?>

Method 3: Traverse the array

In addition to using the built-in functions, you can also calculate the length of the array by traversing the array. The following is a sample code:

<?php //定义一个数组
$array = array(1, 2, 3, 4, 5);

//通过for循环来遍历数组，获取数组元素的个数
$length = 0;
for ($i = 0; isset($array[$i]); $i++) {
    $length++;
}

echo $length; //输出5
?>

Method 4: end function

The end() function is used to point the internal pointer of the array to the last element and return the value of the element. Combining the key() and end() functions, you can get the length of the array. The following is the sample code:

<?php //定义一个数组
$array = array(1, 2, 3, 4, 5);

//通过将内部指针指向数组最后一个元素，结合key()函数获取数组的长度
end($array);
$length = key($array) + 1;

echo $length; //输出5
?>

Method 5: Use the count() function in PHP7

In PHP7, count The () function can accept a countable object (Countable) as a parameter, so you can directly pass the array as a parameter to the count() function to get the length of the array. The following is the sample code:

<?php //定义一个数组
$array = array(1, 2, 3, 4, 5);

//直接将数组作为参数传递给count函数来获取数组的长度
$length = count($array, COUNT_NORMAL);

echo $length; //输出5
?>

In summary , through the above methods, we can easily determine the length of the PHP array. It is worth noting that in actual programming, we should choose the appropriate method according to the specific situation to avoid wasting resources and time.

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