Course Introduction：The sum keyword does not exist in C language, it is a normal identifier and can be used as a variable or function name. But to avoid misunderstandings, it is recommended to avoid using it for identifiers of mathematical-related codes. More descriptive names such as array_sum or calculate_sum can be used to improve code readability.

2025-04-03 comment 0  723

Course Introduction：In PHP, data statistics can be achieved by using built-in functions, custom functions, and third-party libraries. 1) Use built-in functions such as array_sum() and count() to perform basic statistics. 2) Write custom functions to calculate complex statistics such as medians. 3) Use the PHP-ML library to perform advanced statistical analysis. Through these methods, data statistics can be performed efficiently.

2025-05-15 comment 0  751

Course Introduction：To add up all the values ​​in the PHP array at once, the most direct method is to use the array_sum() function, which is suitable for one-dimensional indexes or associative arrays; for arrays with key names, you can use array_column() to extract the corresponding columns and then sum them; if it is a multi-dimensional nested array, it can be achieved through RecursiveIteratorIterator combined with recursive traversal.

2025-07-08 comment 0  285

Course Introduction：Calculate the mean: Use array_sum() to divide by the number of elements to get the mean; 2. Calculate the median: After sorting, take the intermediate value, and take the average of the two intermediate numbers when there are even elements; 3. Calculate the standard deviation: first find the mean, then calculate the average of the squared difference between each value and the mean (the sample is n-1), and finally take the square root; by encapsulating these three functions, basic statistical tools can be constructed, suitable for the analysis of small and medium-sized data, and pay attention to processing empty arrays and non-numerical inputs, and finally realize the core statistical features of the data without relying on external libraries.

2025-07-30 comment 0  133

Course Introduction：SqlParameter Parameters.Add vs. AddWithValue: Choosing the Best MethodWhen working with SQL commands, you may encounter the need to add...

2025-01-10 comment 0  716

Course Elementary  13859

Course Introduction：Scala Tutorial Scala is a multi-paradigm programming language, designed to integrate various features of object-oriented programming and functional programming.

Course Elementary  82403

Course Introduction："CSS Online Manual" is the official CSS online reference manual. This CSS online development manual contains various CSS properties, definitions, usage methods, example operations, etc. It is an indispensable online query manual for WEB programming learners and developers! CSS: Cascading Style Sheets (English full name: Cascading Style Sheets) is an application used to express HTML (Standard Universal Markup Language).

Course Elementary  13209

Course Introduction：SVG is a markup language for vector graphics in HTML5. It maintains powerful drawing capabilities and at the same time has a very high-end interface to operate graphics by directly operating Dom nodes. This "SVG Tutorial" is intended to allow students to master the SVG language and some of its corresponding APIs, combined with the knowledge of 2D drawing, so that students can render and control complex graphics on the page.

Course Elementary  24663

Course Introduction：In the "AngularJS Chinese Reference Manual", AngularJS extends HTML with new attributes and expressions. AngularJS can build a single page application (SPAs: Single Page Applications). AngularJS is very easy to learn.

Course Elementary  27514

Course Introduction：Go is a new language, a concurrent, garbage-collected, fast-compiled language. It can compile a large Go program in a few seconds on a single computer. Go provides a model for software construction that makes dependency analysis easier and avoids most C-style include files and library headers. Go is a statically typed language, and its type system has no hierarchy. Therefore users do not need to spend time defining relationships between types, which feels more lightweight than typical object-oriented languages. Go is a completely garbage-collected language and provides basic support for concurrent execution and communication. By its design, Go is intended to provide a method for constructing system software on multi-core machines.