Golang determines whether the specified key in the map exists

Map is a built-in type in Go that binds keys and values ​​together. The corresponding value can be obtained by key.

A map can be created by passing the key and value types to the built-in function make. The syntax is: make(map[KeyType]ValueType).

Let's take a look at the method of judging whether the key in the map exists:

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

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

For more golang knowledge, please pay attention to the golang tutorial column.

The above is the detailed content of Golang determines whether the specified key in the map exists. For more information, please follow other related articles on the PHP Chinese website!