How to determine if a variable is an array in php

PHP is a very popular programming language and one of the most popular languages ​​for web development. In PHP, array is a very commonly used data type that can store multiple values ​​in the form of an array. In PHP, determining whether a variable is an array requires some specific methods, which we will explain in detail next.

1. Use the is_array() function to determine

PHP provides a built-in function is_array(), which is used to determine whether a variable is an array type. The use of the is_array() function is very simple. You only need to pass the variable to be judged as a parameter to the function. Returns true if the variable is of array type; false if not.

The specific code implementation is as follows:

<?php
  $arr = array(1, 2, 3);
  $str = "Hello World!";
  var_dump(is_array($arr)); // 输出 bool(true)
  var_dump(is_array($str)); // 输出 bool(false)
?>

As can be seen from the above code, the is_array() function can quickly determine whether a variable is an array, which is very convenient and practical.

2. Use gettype() and is_array() functions together

In addition to using is_array() function, you can also use gettype() and is_array() functions together Use to determine whether a variable is an array type. The gettype() function is used to get the type of a variable and returns a string value. Returns "array" if the variable is of type array, or some other value if it is not of type array.

The specific code implementation is as follows:

<?php
  $arr = array(1, 2, 3);
  $str = "Hello World!";
  if (gettype($arr) == "array" && is_array($arr)) {
    echo "arr is an array!"; // 输出 arr is an array!
  }
  if (gettype($str) == "array" && is_array($str)) {
    echo "str is an array!";
  }
?>

As can be seen from the above code, when we need to determine whether a variable is an array type at the same time, we can use the gettype() and is_array() functions Used together, this will be more accurate.

Summary

In PHP, it is very simple to determine whether a variable is an array type. We can use the is_array() function or use the gettype() and is_array() functions together to achieve this. But it should be noted that in PHP, except for the keyword NULL, all values ​​can be regarded as array types, so we need to handle it carefully in actual development to avoid errors.

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