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- How to use php round function?
- PHP's round() function is used to round floating point numbers. The basic usage is to pass in a floating point number, and the integer is rounded by rounding by default; 1. The reserved decimal places can be controlled through the second parameter precision, such as round(3.14159, 2) output 3.14; 2. When precision is negative, carry to the left, such as round(1234.56,-2) output 1200; 3. The third parameter mode can specify the rounding method, and the default PHP_ROUND_HALF_UP is rounded, and PHP_ROUND_HALF_DOWN does not carry. 5; in addition, it is necessary to note that floating point accuracy issues may lead to unexpected results. It is recommended to combine number_fo
- PHP Tutorial . Backend Development 918 2025-07-02 17:25:11
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- How to get last element of php array
- There are the following methods to get the last element of the PHP array: 1. The most direct way to use the end() function, but it will move the internal pointer of the array; 2. Combining array_keys() and count() is suitable for arrays with discontinuous key names; 3. For continuous numeric index arrays, $array[count($array)-1] can be used; 4. Array_pop() will modify the original array, be careful to use it for read-only operations. The selection method should be determined based on the array type and whether the original array and pointer state are allowed to be modified.
- PHP Tutorial . Backend Development 563 2025-07-02 17:23:11
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- How to combine two php arrays unique values?
- 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 $array2, which will ensure that the keys in the first array will not be overwritten by the second array. These two methods are applicable to different scenarios, depending on whether the key name is retained or only the focus is on
- PHP Tutorial . Backend Development 1075 2025-07-02 17:18:13
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- How to shuffle a php array?
- To disrupt the order of PHP arrays, 1. Use the shuffle() function to randomly disrupt the element order and discard the original key name; 2. If you need to retain the key name, you can use array_rand() to rebuild the array with loop; 3. For multi-dimensional arrays, you can still use shuffle() to process the top-level elements, or combine usort() with random comparison functions to implement more complex sorting logic. These methods can be selected and used according to specific needs.
- PHP Tutorial . Backend Development 367 2025-07-02 17:09:30
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- How to convert php array to string?
- To convert PHP arrays into strings, the most common method is to use the implode() function 1.implode() accepts connectors and arrays as parameters, and concatenates array elements into strings with specified characters; 2. For multi-dimensional arrays, they must be "flattened" into one-dimensional arrays through array_column() or recursively before converting; 3. To preserve the key-value pair relationship, you can use http_build_query() to generate a string in the form of URL query parameters; in addition, before processing, you should ensure that the array elements are of string type, and if necessary, you can use array_map('strval',$array) to convert.
- PHP Tutorial . Backend Development 812 2025-07-02 17:02:10
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- How to create an array in php?
- 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
- PHP Tutorial . Backend Development 283 2025-07-02 17:01:10
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- php raw post data php
- The way to process raw POST data in PHP is to use $rawData=file_get_contents('php://input'), which is suitable for receiving JSON, XML, or other custom format data. 1.php://input is a read-only stream, which is only valid in POST requests; 2. Common problems include server configuration or middleware reading input streams, which makes it impossible to obtain data; 3. Application scenarios include receiving front-end fetch requests, third-party service callbacks, and building RESTfulAPIs; 4. The difference from $_POST is that $_POST automatically parses standard form data, while the original data is suitable for non-standard formats and allows manual parsing; 5. Ordinary HTM
- PHP Tutorial . Backend Development 558 2025-07-02 16:51:11
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- How to convert json string to php array?
- Use the json_decode function and set the second parameter to true to convert the JSON string to PHP array; 1. The usage is $array=json_decode($jsonString,true); 2. If the second parameter is not added, the stdClass object will be returned; 3. Make sure that the input string is valid JSON, otherwise it will return null; 4. You can check errors through json_last_error(); 5. Common errors include format problems such as unclosed quotes, redundant commas, etc.; 6. After the conversion in the example, you can access the corresponding value through the array key; as long as you pay attention to the format and parameter settings, the conversion can be completed smoothly.
- PHP Tutorial . Backend Development 421 2025-07-02 16:48:41
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- How to remove element from php array?
- There are three ways to delete array elements in PHP: use unset() to delete elements of the specified key, use array_diff() to delete specific values, and use array_filter() to filter by condition. 1. unset($array[key]) directly deletes elements of the specified key, but does not reset the index; 2.array_diff($array,[values]) deletes one or more specified values, and returns a new array and needs to be reassigned; 3.array_filter($array,callback) filters retained elements according to callback function conditions, which is suitable for complex logic. Note: If continuous indexes are required after unset(), it should be combined with array_v
- PHP Tutorial . Backend Development 659 2025-07-02 16:41:30
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- php post data size limit
- The POST data size limit in PHP is mainly determined by multiple configuration items. When encountering the problem of "POST data is too large", the solutions include: 1. Modify the post_max_size parameter to control the maximum POST data that PHP can receive. It is recommended to set it to be slightly larger than the maximum file sum allowed to be uploaded; 2. Set upload_max_filesize to control the upper limit of a single file, adjust memory_limit to ensure sufficient memory; 3. Check the client_max_body_size configuration of a web server such as Nginx and increase it appropriately; 4. If php.ini cannot be modified, you can try to pass .htaccess or ini_set()
- PHP Tutorial . Backend Development 185 2025-07-02 16:09:10
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- How to call a php function
- The methods to call PHP functions include directly using the function name with brackets, passing parameters, and paying attention to related rules. The basic steps are: 1. Use built-in functions or custom functions, such as echostrlen("Hello") or sayHello(); 2. Pay attention to the order and type when passing parameters, and use default values, such as greet("Alice") or greet("Bob","Hello"); 3. Calling methods in the class requires creating an object first, and then calling it through the object, such as $g->say("Tom"); 4. Notes include avoiding
- PHP Tutorial . Backend Development 321 2025-07-02 15:48:13
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- How to flatten a multi dimensional php array?
- How to flatten a multidimensional array? 1. Use recursive functions to manually traverse the array. If the elements are still arrays, continue to go deeper until all values ??are collected; 2. Use PHP's built-in RecursiveIteratorIterator and RecursiveArrayIterator to achieve automatic expansion; Note: Both methods discard the original key names by default. If you need to retain the logic, you should modify it and deal with the overwrite of duplicate keys.
- PHP Tutorial . Backend Development 942 2025-07-02 15:47:10
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- How to use php array_filter function?
- array_filter is used to filter elements in an array that meet the criteria. It is useful when you need to filter null values, specific values, or filter by rules, such as string length, such as removing false values, retaining even numbers, or long strings. When using it, you can choose whether to pass the callback function: if you do not pass, false values ??such as false, null will be automatically filtered; if you pass, it will decide whether to keep it based on the callback return true or false. In addition, the filtering can be done by combining the key name with the ARRAY_FILTER_USE_BOTH parameter and the index can be reset using array_values.
- PHP Tutorial . Backend Development 657 2025-07-02 15:44:11
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- How to remove element from php array
- To delete elements in PHP array, you need to select the method according to the scene. 1. Use unset() to delete elements of the specified key, which is suitable for the known key name, but will not be re-indexed; 2. Use array_diff() to delete by value, and the same value can be deleted in batches, which is slightly less efficient; 3. Array_diff_key() can be deleted by different key names; 4. Array_filter() supports custom logical filtering and deletion, which is highly flexible; 5. Array_splice() can be deleted by position and quantity, and the index is automatically re-arranged. Different methods are suitable for different requirements, pay attention to the processing and performance impact of keys.
- PHP Tutorial . Backend Development 374 2025-07-02 15:35:10
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