PHP string object converted into array object array object

In PHP, we often encounter situations where we need to convert a string into an array or object. Strings are generally used to read data from the outside or output data to the user, while arrays and objects are more suitable for data manipulation and processing. This article will introduce how to convert strings into objects and arrays, and provide some common application scenarios and examples.

1. Convert a string into an object

Use the built-in function json_decode() to convert a string in JSON format into an object in PHP, for example:

$json_str = '{"username": "Tom", "age": 20}';
$obj = json_decode($json_str);

echo $obj->username; //输出Tom
echo $obj->age; //输出20

In In the above code, the json_decode() function converts the JSON format string into an object and saves it in the $obj variable. We can then use $obj to access members in the object, such as $username and $age.

In addition to using the json_decode() function, we can also use the serialize() function to serialize the object into a string, and then use the unserialize() function to deserialize the string into an object, for example:

class Person {
    public $name;
    public $age;
}

$person = new Person();
$person->name = 'John';
$person->age = 30;

$str = serialize($person);
$obj = unserialize($str);

echo $obj->name; //输出John
echo $obj->age; //输出30

In the above code, we define a Person class and use two member variables $name and $age to save the person's name and age. Then, we created the $person object, serialized the object into a string, and then deserialized the string into an object through the unserialize() function. Finally, we can use the $obj variable to access the deserialized object.

It should be noted that when using the unserialize() function, you need to ensure that the incoming string is generated by the serialize() function, otherwise unexpected errors may occur.

2. Convert a string into an array

In PHP, use the built-in function explode() to split a string into an array according to the specified delimiter. For example:

$str = 'apple,banana,orange';
$arr = explode(',', $str);

print_r($arr);

In the above code, we use commas as delimiters to split the string "apple, banana, orange" into an array, and then output the entire array through the print_r() function. The output result is as follows:

Array
(
    [0] => apple
    [1] => banana
    [2] => orange
)

In addition, you can also use the built-in function preg_split() to perform regular expression splitting on the string, for example:

$str = 'apple,banana and orange';
$arr = preg_split('/[,s]+/', $str);

print_r($arr);

In the above code, we Use the regular expression "/[,s] /" as the delimiter to split the string "apple, banana and orange" into an array. It should be noted that "[,s]" in the regular expression here means matching one or more commas or spaces.

In addition to using the explode() and preg_split() functions, we can also use the json_decode() function to convert JSON-formatted strings into arrays in PHP. For example:

$json_str = '["apple", "banana", "orange"]';
$arr = json_decode($json_str, true);

print_r($arr);

In the above code, we use the json_decode() function to convert the JSON format string "["apple", "banana", "orange"]" into a PHP array.

3. Common application scenarios

Converting strings into objects or arrays is often used in the following two situations:

1. Reading external data

When reading data from the outside, the data generally exists in the form of a string. We need to convert the string into an object or array in PHP for operation. For example, when reading data from the database, it is usually read in the form of a string, and we need to convert it into a PHP object or array for operation.

2. Output to users

When we need to output data to users, we often need to convert PHP objects or arrays into string format for output. For example, when we need to output data into JSON format, we need to convert the PHP object or array into a JSON format string for output.

4. Conclusion

This article introduces how to convert strings into objects and arrays, and provides some common application scenarios and examples. When we need to convert a string into an object or array in PHP, we can use built-in functions such as json_decode(), serialize(), and preg_split(). These functions are not only simple to use, but also have high performance and can meet the needs of most application scenarios.

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