Functions are the basic unit of organizing code in C, used to realize code reuse and modularization; 1. Functions are created through declarations and definitions, such as intadd(inta,intb) returns the sum of the two numbers; 2. Pass parameters when calling the function, and return the result of the corresponding type after the function is executed; 3. The function without return value uses void as the return type, such as voidgreet(stringname) for outputting greeting information; 4. Using functions can improve code readability, avoid duplication and facilitate maintenance, which is the basic concept of C programming.

decltype is a keyword used by C 11 to deduce expression types at compile time. The derivation results are accurate and do not perform type conversion. 1. decltype(expression) only analyzes types and does not calculate expressions; 2. Deduce the variable name decltype(x) as a declaration type, while decltype((x)) is deduced as x due to lvalue expression; 3. It is often used in templates to deduce the return value through tail-set return type auto-> decltype(t u); 4. Complex type declarations can be simplified in combination with auto, such as decltype(vec.begin())it=vec.begin(); 5. Avoid hard-coded classes in templates

This article introduces in detail how to use jQuery to implement the "Select All/No Select All" function of multiple sets of check boxes to ensure that each set of check boxes is operated in an independent HTML container without affecting each other. By adding specific class names to the parent container and the "Select All" check box, combined with jQuery's event listening, DOM traversal and property operations, we can control the selected status of all check boxes in the same group when clicking "Select All" and reverse linkage, that is, when all check boxes in the same group are automatically selected, or when any check box is unchecked, "Select All" is automatically cancelled.

C folderexpressions is a feature introduced by C 17 to simplify recursive operations in variadic parameter templates. 1. Left fold (args...) sum from left to right, such as sum(1,2,3,4,5) returns 15; 2. Logical and (args&&...) determine whether all parameters are true, and empty packets return true; 3. Use (std::cout

This article details how to efficiently load associated data on conditional basis in LaravelEloquent. By utilizing the closure function of the with() method, developers can flexibly define specific query conditions for the association model, thereby accurately obtaining the required subset of data. The tutorial covers basic usage, nested association conditional loading, and distinguishes it from database foreign key constraints, aiming to improve the efficiency and accuracy of data queries.

In relational databases, it is not supported to directly define "conditional foreign keys" to implement foreign key constraints based on specific values. However, at the application layer, we can flexibly implement conditional loading and filtering of associated data through query builders (such as LaravelEloquent), thereby achieving a "conditional connection" effect. This article will introduce in detail how to use the with method and its closure parameters in LaravelEloquent, conditional filtering of the association model, and how to use whereHas to filter the main model.

Writing high-performance Java code requires understanding the JVM, using language features reasonably, and avoiding common pitfalls. 1. Avoid creating unnecessary objects, and use StringBuilder to prioritize string splicing to reduce GC pressure; 2. Specify reasonable capacity when initializing the set to avoid performance overhead caused by frequent expansion; 3. Priority types rather than packaging types to avoid performance losses caused by automatic boxing and unboxing. Special libraries such as TIntArrayList can be selected in performance-sensitive scenarios; 4. Priority is used such as ConcurrentHashMap and LongAdder in multi-threaded environments to avoid excessive use of synchronized; 5. Keep the method short to facilitate JIT

ABinarySearchTree(BST)isabinarytreewheretheleftsubtreecontainsonlynodeswithvalueslessthanthenode’svalue,therightsubtreecontainsonlynodeswithvaluesgreaterthanthenode’svalue,andbothsubtreesmustalsobeBSTs;1.TheC implementationincludesaTreeNodestructure