javascript - 如何将从 firebase 读取的值分配给变量

Question

我试图从 firebase 读取值并将其分配给全局变量，但它不起作用。

    public points: any;

    readPoints(): any{
        this.userProfile.child(this.user.uid).once('value').then((snapshot) =>{
            this.points = snapshot.val().user_points;
        });
    }
    console.log(this.points); //undefined




 Users{
          SAdS4cW57DSLuWr2obbZYUHsmAL2{
                user_points: 20
.....

Answer 1

好吧，你的变量是 this.points 但你正在尝试打印 this.point