Do php array key values ​​distinguish types?

PHP array key values ​​are not type-sensitive, because PHP will automatically cast the data type of the key value or value when used. This means that if you use a string key value, you can use an integer as an index, and if you use a non-string key value, PHP will automatically convert it to a string.

Operating system for this tutorial: Windows 10 system, php8.1.3 version, Dell G3 computer.

The key values ​​of PHP arrays are not type-sensitive, because PHP will automatically cast the data type of the key value or value when used.

This means that if you use string key values, you can use integers as indexes, and if you use non-string key values, PHP will automatically convert them to strings.

For example, in this example, you can see the output when using integers and strings as array keys:

<?php
// 创建一个数组
$array = array(
    1 => &#39;one&#39;,
    &#39;2&#39; => &#39;two&#39;,
    3 => &#39;three&#39;,
    &#39;four&#39;
);
// 输出数组的值 
var_dump($array);
?>

The output is as follows:

array(4) {
    [1]=>
    string(3) "one"
    ["2"]=>
    string(3) "two"
    [3]=>
    string(5) "three"
    [4]=>
    string(4) "four"
}

Okay See, the integer indexes are preserved and output as integers, while the string indexes are converted to strings and quotes are shown in the output.

To know exactly what type a key value is, you can use functions such as is_int() and is_string() to check their data type. The following is a sample code that shows how to use these functions to check the type of a key value:

<?php
$my_array = array("apple" => 1, "banana" => "yellow", "cherry" => 3.14);
if (is_int($my_array["apple"])) {
  echo "The apple key is an integer.";
} else if (is_string($my_array["apple"])) {
  echo "The apple key is a string.";
}
if (is_int($my_array["banana"])) {
  echo "The banana key is an integer.";
} else if (is_string($my_array["banana"])) {
  echo "The banana key is a string.";
}
?>

In the above code, we use the is_int() and is_string() functions to check "apple" in the array respectively , the data type of the "banana" key value.

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