Go - Function

Overview

learn some basic grammar, I began to learn to write a function, a function to share a few of his own writing.

    MD5

    Get current timestamp

    acquires the current time string

    generates a signature

function definition

  

FUNCTION_NAME FUNC (Type1 INPUT1, INPUT2 Type2) (Type1, Type2) {     
       // function body     
       // return multiple values     
       return VALUE1, value2     
    }

 

    Function with func statement.

    Function can have one or more parameters, parameter types needed, with segmentation.

    Function may return one or more values, the need for the return type, with segmentation.

    Parameter is optional function, the return value is optional.

Value passed

when the transfer parameters, the parameters passed to the copy function, after adjusting the parameters, the parameter values do not affect.

Go default language is passed by value.
Passed by reference

when parameters are passed, the address parameter is passed to a function, after adjusting the parameters, the influence parameter.

This is Go - example Struct structure:

 

   //demo_13.go    
    package main    
    import (    
        "encoding/json"    
        "fmt"    
    )    
    type Result struct {    
        Code    int    `json:"code"`    
        Message string `json:"msg"`    
    }    
    func main() {    
        var res Result    
        res.Code    = 200    
        res.Message = "success"    
        toJson(&res)    
        setData(&res)    
        toJson(&res)    
    }    
    func setData (res *Result) {    
        res.Code    = 500    
        res.Message = "fail"    
    }    
    func toJson (res *Result) {    
        jsons, errs := json.Marshal(res)    
        if errs != nil {    
            fmt.Println("json marshal error:", errs)    
        }    
        fmt.Println("json data :", string(jsons))    
    }

 

Operating results:

MD5

    // MD5 方法    
    func MD5(str string) string {    
        s := md5.New()    
        s.Write([]byte(str))    
        return hex.EncodeToString(s.Sum(nil))    
    }    
    str := "12345"    
    fmt.Printf("MD5(%s): %s\n", str, MD5(str))

 

The result:


get the current time string

    // xxxx-xx-xx xx:xx:xx    
    func getTimeStr() string {    
        return time.Now().Format("2006-01-02 15:04:05")    
    }    
    fmt.Printf("current time str : %s\n", getTimeStr())

 

The result:


get the current timestamp

    // 获取当前时间戳    
    func getTimeInt() int64 {    
        return time.Now().Unix()    
    }    
    fmt.Printf("current time str : %s\n", getTimeStr())    
    fmt.Printf("current time unix : %d\n", getTimeInt())

 

The result:

generating a signature

 

  //demo_26.go    
    package main    
    import (    
        "crypto/md5"    
        "encoding/hex"    
        "fmt"    
        "sort"    
    )    
    func main() {    
        params := map[string]interface{} {    
            "name" : "Tom",    
            "pwd"  : "123456",    
            "age"  : 30,    
        }    
        fmt.Printf("sign : %s\n", createSign(params))    
    }    
    // MD5 方法    
    func MD5(str string) string {    
        s := md5.New()    
        s.The Write ([] byte (STR))    
    // signature is generated    
        return hex.EncodeToString(s.Sum(nil))    
    }    
    func createSign(params map[string]interface{}) string {    
        var key []string    
        var str = ""    
        for k := range params {    
            key   = append(key, k)    
        }    
        sort.Strings(key)    
        for i := 0; i < len(key); i++ {    
            if i == 0 {    
                str = fmt.Sprintf("%v=%v", key[i], params[key[i]])    
            } else {    
                str = str + fmt.Sprintf("&xl_%v=%v", key[i], params[key[i]])    
            }    
        }    
        // 自定义密钥    
        var secret = "123456789"    
        // Custom Signature Algorithm    
        sign := MD5(MD5(str) + MD5(secret))    
        return sign    
    }

 

The result:


the corresponding PHP to generate a signature method:



Interested parties can in the signature process, increasing the time stamp and secret reading in the configuration file.