Go language provides two dynamic function creation technologies: closure and reflection. closures allow access to variables within the closure scope, and reflection can create new functions using the FuncOf function. These technologies are useful in customizing HTTP routers, implementing highly customizable systems, and building pluggable components.

1. The SUM function is used to sum the numbers in a column or a group of cells, for example: =SUM(A1:J10). 2. The AVERAGE function is used to calculate the average of the numbers in a column or a group of cells, for example: =AVERAGE(A1:A10). 3. COUNT function, used to count the number of numbers or text in a column or a group of cells, for example: =COUNT(A1:A10) 4. IF function, used to make logical judgments based on specified conditions and return the corresponding result.

When passing a map to a function in Go, a copy will be created by default, and modifications to the copy will not affect the original map. If you need to modify the original map, you can pass it through a pointer. Empty maps need to be handled with care, because they are technically nil pointers, and passing an empty map to a function that expects a non-empty map will cause an error.

In C++ function naming, it is crucial to consider parameter order to improve readability, reduce errors, and facilitate refactoring. Common parameter order conventions include: action-object, object-action, semantic meaning, and standard library compliance. The optimal order depends on the purpose of the function, parameter types, potential confusion, and language conventions.

Exception handling in C++ can be enhanced through custom exception classes that provide specific error messages, contextual information, and perform custom actions based on the error type. Define an exception class inherited from std::exception to provide specific error information. Use the throw keyword to throw a custom exception. Use dynamic_cast in a try-catch block to convert the caught exception to a custom exception type. In the actual case, the open_file function throws a FileNotFoundException exception. Catching and handling the exception can provide a more specific error message.

The strlen function is used to obtain the length of a string, that is, the number of valid characters in the string: Syntax: size_t strlen(const char *str); Parameters: str: the string whose length is to be calculated, a character pointer ending with 0; return Value: Returns the number of characters in the string str, excluding the 0-terminating character.

Function return value is crucial in C++, which allows the function to return data of a specified type: the return value type defines the type of data returned by the function, including basic types (such as int, float) and custom types (such as pointers, references). The return value meaning varies based on the function's intent, such as returning a result, indicating status, providing a reference, or creating a new object.

Original title: "These 3 Excel financial functions are undervalued again!" 》Author of this article: Xiaohua Editor of this article: Zhu Lan Recently, Xiaohua encountered an interesting question, which came from the soul of an old friend: How to choose between monthly annuity and private mutual insurance finance? The basic information of these two financial products is as follows: Monthly annuity: monthly payment of 1,000 yuan, annualized interest rate of 3%, 2-year term, and one-time withdrawal of principal and interest upon maturity. Mutual insurance finance: Pay a principal of 1,000 yuan every month, and the monthly principal will be calculated at 10% interest, with a 2-year term. There are 24 people participating in the same product. Every month, one person must receive all the principal and interest paid by others. The next month after receiving the payment, one person must pay an interest of 100 yuan/month. How to compare the pros and cons of these two financial products? we can