Firebase调用后无法访问的变量 [英] variable no accessible after a Firebase call

问题描述

我正在使用Firebase来访问相同的数据，但是我无法在用于访问它的功能中使用这些数据。
如何使刚访问的数据而不是初始值成为控制台日志？

I'm using Firebase to access to same data, but i can't use the data out of the function used to access it. How i can make a console log of the data just accessed instead of the initial value?

var whatNeed = 'hello';
gameData = new Firebase('https://thegame.firebaseio.com/gameData');
    gameData.on("value", function(snapshot) {
        var data = snapshot.val();
        whatNeed = data.property;
    });
console.log(whatNeed);

推荐答案

需要在回调之外被调用时将始终包含初始值，因为 value console.log $ c>事件处理程序是异步的。

whatNeed will always contain the initial value when called outside of your callback as the console.log will be called first since the value event handler is asynchronous.

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