Go's switch statement will not be executed throughout the process by default and will automatically exit after matching the first condition. 1. Switch starts with a keyword and can carry one or no value; 2. Case matches from top to bottom in order, only the first match is run; 3. Multiple conditions can be listed by commas to match the same case; 4. There is no need to manually add break, but can be forced through; 5.default is used for unmatched cases, usually placed at the end.

AruneinGoisaUnicodecodepointrepresentedasanint32,usedtocorrectlyhandleinternationalcharacters;1.Userunesinsteadofbytestoavoidsplittingmulti-byteUnicodecharacters;2.Loopoverstringswithrangetogetrunes,notbytes;3.Convertastringto[]runetosafelymanipulate

Using bufio.Scanner is the most common and efficient method in Go to read files line by line, and is suitable for handling scenarios such as large files, log parsing or configuration files. 1. Open the file using os.Open and make sure to close the file via deferfile.Close(). 2. Create a scanner instance through bufio.NewScanner. 3. Call scanner.Scan() in the for loop to read line by line until false is returned to indicate that the end of the file is reached or an error occurs. 4. Use scanner.Text() to get the current line content (excluding newline characters). 5. Check scanner.Err() after the loop is over to catch possible read errors. This method has memory effect

The answer is: Go applications do not have a mandatory project layout, but the community generally adopts a standard structure to improve maintainability and scalability. 1.cmd/ stores the program entrance, each subdirectory corresponds to an executable file, such as cmd/myapp/main.go; 2.internal/ stores private code, cannot be imported by external modules, and is used to encapsulate business logic and services; 3.pkg/ stores publicly reusable libraries for importing other projects; 4.api/ optionally stores OpenAPI, Protobuf and other API definition files; 5.config/, scripts/, and web/ store configuration files, scripts and web resources respectively; 6. The root directory contains go.mod and go.sum

To import local packages correctly, you need to use the Go module and follow the principle of matching directory structure with import paths. 1. Use gomodinit to initialize the module, such as gomodinitexample.com/myproject; 2. Place the local package in a subdirectory, such as mypkg/utils.go, and the package is declared as packagemypkg; 3. Import it in main.go through the full module path, such as import "example.com/myproject/mypkg"; 4. Avoid relative import, path mismatch or naming conflicts; 5. Use replace directive for packages outside the module. Just make sure the module is initialized

Routing in Go applications depends on project complexity. 1. The standard library net/httpServeMux is suitable for simple applications, without external dependencies and is lightweight, but does not support URL parameters and advanced matching; 2. Third-party routers such as Chi provide middleware, path parameters and nested routing, which is suitable for modular design; 3. Gin has excellent performance, built-in JSON processing and rich functions, which is suitable for APIs and microservices. It should be selected based on whether flexibility, performance or functional integration is required. Small projects use standard libraries, medium and large projects recommend Chi or Gin, and finally achieve smooth expansion from simple to complex.

BuildconstraintsinGoarecommentslike//go:buildthatcontrolfileinclusionduringcompilationbasedonconditionssuchasOS,architecture,orcustomtags.2.TheyareplacedbeforethepackagedeclarationwithablanklineinbetweenandsupportBooleanoperatorslike&&,||,and

Go's flag package can easily parse command line parameters. 1. Use flag.Type() to define type flags such as strings, integers, and booleans; 2. You can parse flags to variables through flag.TypeVar() to avoid pointer operations; 3. After calling flag.Parse(), use flag.Args() to obtain subsequent positional parameters; 4. Implementing the flag.Value interface can support custom types to meet most simple CLI requirements. Complex scenarios can be replaced by spf13/cobra library.