[Go] 解决golang中出现 panic: runtime error: invalid memory address or nil pointer dereference

package tools

import "fmt"

func MyTest() {
    type MConn struct {
        Name string
    }
    var conn *MConn
    var conn2 MConn
    conn3 := new(MConn)
    conn4 := &MConn{}
    fmt.Printf("%v,%v,%v,%v", conn, conn2, conn3, conn4)
}

    var mMap map[string]*MConn
    m1 := mMap["name"]
    m1.Name = "qqq"

    var mMap map[string]*MConn
    m1, ok := mMap["name"]
    if ok {
        m1.Name = "qqq"
    }