The method of golang to judge whether the key exists in the map is: [value,ok:map[key]], when ok is true, it exists, such as [_,ok:demo[“a”]fmt.Println(ok)].

The judgment method is value, ok := map[key], if ok is true, it exists.

Recommended video tutorial: go basic tutorial

Examples are as follows:

package main
  
import "fmt"
  
func main() {
  
     demo := map[string]bool{
         "a": false,
     }
  
     //Error, a exists, but returns false
     fmt.Println(demo["a"])
  
     //Correct judgment method
     _, ok := demo["a"]
     fmt.Println(ok)
}

false
true