浅析Golang如何向已关闭的chan读写数据

package main

func main() {
	// 创建缓冲区为4的字符串chan
	schoolChan := make(chan string, 4)
	// 放入3个值
	schoolChan <- "国防科大"
	schoolChan <- "北京大学"
	schoolChan <- "湖南大学"

	// 关闭chan
	close(schoolChan)

	// 尝试写数据，会panic: send to close channel
	schoolChan <- "中南大学"
}

package main

import "fmt"

func main() {
	// 创建缓冲区为4的字符串chan
	schoolChan := make(chan string, 4)
	// 放入3个值
	schoolChan <- "国防科大"
	schoolChan <- "北京大学"
	schoolChan <- "湖南大学"

	// 关闭chan
	close(schoolChan)

	// 向已关闭的chan读
	if school, isEmpty := <-schoolChan; isEmpty {
		fmt.Println("school:", school)
	}

	// 向已关闭的chan读
	if school, isEmpty := <-schoolChan; isEmpty {
		fmt.Println("school:", school)
	}

	// 向已关闭的chan读
	if school, isEmpty := <-schoolChan; isEmpty {
		fmt.Println("school:", school)
	}

	// 向若chan不存在元素，则第二个参数的值为 false
	if school, isEmpty := <-schoolChan; isEmpty {
		fmt.Println("school:", school)
	}
}

package main

import (
	"fmt"
)

func main() {
	// 创建缓冲区为4的字符串chan
	schoolChan := make(chan string, 4)
	// 放入3个值
	schoolChan <- "国防科大"
	schoolChan <- "北京大学"
	schoolChan <- "湖南大学"

	// 关闭chan
	close(schoolChan)

	// for循环遍历channel，会将已关闭的chan中缓冲区的数据取出完后终止循序
	for school := range schoolChan {
		fmt.Println("school:", school)
	}
}