To merge two PHP arrays and keep unique values, there are two main methods. 1. For index arrays or only deduplication, use array_merge and array_unique combinations: first merge array_merge($array1,$array2) and then use array_unique() to deduplicate them to finally get a new array containing all unique values; 2. For associative arrays and want to retain key-value pairs in the first array, use the operator: $result=$array1 $array2, which will ensure that the keys in the first array will not be overwritten by the second array. These two methods are applicable to different scenarios, depending on whether the key name is retained or only the focus is on

There are two ways to create an array in PHP: use the array() function or use brackets []. 1. Using the array() function is a traditional way, with good compatibility. Define index arrays such as $fruits=array("apple","banana","orange"), and associative arrays such as $user=array("name"=>"John","age"=>25); 2. Using [] is a simpler way to support since PHP5.4, such as $color

The way to access nested JSON objects in Python is to first clarify the structure and then index layer by layer. First, confirm the hierarchical relationship of JSON, such as a dictionary nested dictionary or list; then use dictionary keys and list index to access layer by layer, such as data "details"["zip"] to obtain zip encoding, data "details"[0] to obtain the first hobby; to avoid KeyError and IndexError, the default value can be set by the .get() method, or the encapsulation function safe_get can be used to achieve secure access; for complex structures, recursively search or use third-party libraries such as jmespath to handle.

Processing JSON data is very common in Python, especially when interacting with network requests and APIs. The following are common operations: 1. Use json.loads() to parse JSON strings into Python objects (such as dictionaries or lists), which is suitable for processing after obtaining data from the API; 2. Use json.dumps() to serialize Python objects into JSON strings, which is suitable for sending data or saving configuration files, and can optimize the output format through indent and ensure_ascii parameters; 3. Use json.load() and json.dump() to read and write JSON files respectively, which is suitable for processing local configuration or batch data; pay attention to load

MySQL supports JSON data types introduced since version 5.7 to handle structured and semi-structured data. 1. When inserting JSON data, you must use a legal format. You can use JSON_OBJECT or JSON_ARRAY functions to construct, or pass in the correct JSON string; 2. Updates should use JSON_SET, JSON_REPLACE, JSON_REMOVE to modify some fields instead of the entire replacement; 3. Query can extract fields through JSON_CONTAINS, -> operators, and note that the string value needs to be double quoted; 4. It is recommended to create a generated column and index to improve performance when using JSON type.

There are three common ways to parse JSON in Java: use Jackson, Gson, or org.json. 1. Jackson is suitable for most projects, with good performance and comprehensive functions, and supports conversion and annotation mapping between objects and JSON strings; 2. Gson is more suitable for Android projects or lightweight needs, and is simple to use but slightly inferior in handling complex structures and high-performance scenarios; 3.org.json is suitable for simple tasks or small scripts, and is not recommended for large projects because of its lack of flexibility and type safety. The choice should be decided based on actual needs.

Reading JSON files can be implemented in Python through the json module. The specific steps are: use the open() function to open the file, use json.load() to load the content, and the data will be returned in a dictionary or list form; if you process JSON strings, you should use json.loads(). Common problems include file path errors, incorrect JSON format, encoding problems and data type conversion differences. Pay attention to path accuracy, format legality, encoding settings, and mapping of boolean values and null.

TocreateabasicrouteinYii,firstsetupacontrollerbyplacingitinthecontrollersdirectorywithpropernamingandclassdefinitionextendingyii\web\Controller.1)Createanactionwithinthecontrollerbydefiningapublicmethodstartingwith"action".2)ConfigureURLstr