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HomeBackend DevelopmentGolangGolang's method to determine if the key in the map does not exist

Golang's method to determine if the key in the map does not exist

#go languageIn map, map is a set of kv pairs. The bottom layer uses a hash table and a linked list to resolve conflicts. Through the compiler and runtime, all map objects share the same code.

Golang’s method of judging whether the key in the map does not exist:

The judgment method is value,ok := map[key], if ok is true, it exists, if ok is false, the key of the map does not exist. .

package main
 
import "fmt"
 
func main() {
 
    demo := map[string]bool{
        "a": false,
    }
 
    //错误,a存在,但是返回false
    fmt.Println(demo["a"])
 
    //正确判断方法
    _, ok := demo["a"]
    fmt.Println(ok)
}

Output

false
true

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