How to remove arrays that are not integers in php

In PHP, sometimes we need to operate on integer elements in an array. However, if there are elements of non-integer type in the array, this may cause errors in subsequent calculation operations. Therefore, we need to find a way to remove these non-integer elements.

Below, I will introduce several methods to achieve this function.

Method 1: Use the is_int() function to filter

The is_int() function can determine whether a variable is an integer. We can iterate through each element in the array and use the is_int() function to determine whether it is an integer type. If it is an integer, add it to the new array, otherwise ignore the element.

The following is a code example:

$array = array(1, 2, "foo", 3.5, "bar", 4);

$new_array = array();

foreach ($array as $value) {
    if (is_int($value)) {
        $new_array[] = $value;
    }
}

print_r($new_array); // 输出：Array ( [0] => 1 [1] => 2 [2] => 4 )

In this example, we define a primitive array $array, which contains integers, strings and floating point numbers. By traversing the array, we use the is_int() function to determine whether each element is an integer type. Finally, we add all integer elements to the new array $new_array.

Method 2: Use the ctype_digit() function to filter

In addition to the is_int() function, PHP also provides a ctype_digit() function, which can be used to determine whether a string only contains numeric characters. Therefore, we can convert the non-integer element in the array to a string type, and then use the ctype_digit() function to determine whether it is an integer type.

The following is a code example:

$array = array(1, 2, "foo", 3.5, "bar", 4);

$new_array = array();

foreach ($array as $value) {
    if (ctype_digit(strval($value))) {
        $new_array[] = (int) $value;
    }
}

print_r($new_array); // 输出：Array ( [0] => 1 [1] => 2 [2] => 4 )

In this example, we first convert each element in the array to a string type, and then use the ctype_digit() function to determine whether it is an integer type . Finally, if it is an integer type, it is converted to an integer type and added to the new array $new_array.

Method 3: Use the array_filter() function to filter

PHP’s built-in array_filter() function can filter the elements in the array and return a new array. We can use this function to quickly remove non-integer elements from an array.

The following is a code example:

$array = array(1, 2, "foo", 3.5, "bar", 4);

$new_array = array_filter($array, 'is_int');

print_r($new_array); // 输出：Array ( [0] => 1 [1] => 2 [5] => 4 )

In this example, we directly use the array_filter() function to filter the elements in the array and retain the elements of integer type. Note that this function will only retain the values ​​of the elements, not their previous subscripts.

Summary

The above are several ways to remove non-integer elements from an array. Different methods are suitable for different situations and need to be selected according to the actual situation. When using the is_int() function and ctype_digit() function, you need to pay attention to type conversion issues. When using the array_filter() function, you need to pay attention to the change of element subscripts. Mastering these methods can help us operate the integer elements in the array more efficiently.

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