for-select.md

for select

https://wudaijun.com/2017/10/go-select/

• return 退出

    package main 
    
    import (
    	"time"
    	"fmt"
    	)
    func main() {
    	c1 := make(chan string)
    	c2 := make(chan string)
    
    	go func() {
    		time.Sleep(time.Second * 1);
    		c1 <- "one"
    	}()
    
    	go func() {
    		time.Sleep(time.Second * 2)
    		c2 <- "two"
    	}()
    	
    
    
    	
    
    	for {
    		select {
    			case msg1 := <-c1:
    				fmt.Println("receiveed", msg1)
    			case msg2 := <-c2:
    				fmt.Println("receiveed", msg2) 
    				return 
    		}
    	}
    
    
    	for i := 0; i < 2; i++ {
    		select {
    			case msg1 := <-c1:
    				fmt.Println("receiveed", msg1)
    			case msg2 := <-c2:
    				fmt.Println("receiveed", msg2) 
    		}
    	}
    }
  

• break 退出

    forTag:
    for {
    	select {
    		case msg1 := <-c1:
    			fmt.Println("receiveed", msg1)
    		case msg2 := <-c2:
    			fmt.Println("receiveed", msg2) 
    			break forTag
    	}
    }
  

• goto退出

    for {
    	select {
    		case msg1 := <-c1:
    			fmt.Println("receiveed", msg1)
    		case msg2 := <-c2:
    			fmt.Println("receiveed", msg2) 
    			goto gotoTag
    	}
    }
    gotoTag: