javascript - 新手尝试让 localStorage 工作

Question

我无法让下面的代码表达除未定义以外的任何内容。我什么地方做得不对？我也不确定分数函数是如何工作的。到目前为止，我只编写了普通的 function doSomething() {} 方法。谢谢。

var score = score || {};

score = {
  saveHighScore: function(tally) {
    var high_score = localStorage.high_score;
    if (typeof high_score == 'number') {
      if (tally > high_score) {
        localStorage.high_score = tally;
      }
    } else {
      localStorage.high_score = tally;
    }
  },
  getHighScore: function() {
    var high_score = localStorage.high_score;
    if(typeof high_score !== 'number') {
      high_score = 0;
      localStorage.high_score = high_score;
    }
    return high_score;
  }
}

window.console.log("Score: ", score.getHighScore());

Answer 1

您的问题是本地存储将值存储为字符串键/值对，因此您需要 parseInt:-

var score = score || {};

score = {
  saveHighScore: function(tally) {
    var high_score = localStorage.high_score;
    if (typeof high_score == 'number') {
      if (tally > high_score) {
        localStorage.high_score = tally;
      }
    } else {
      localStorage.high_score = tally;
    }
  },
  getHighScore: function() {
    var high_score = parseInt(localStorage.high_score);
    if(typeof high_score !== 'number') {
      high_score = 0;
      localStorage.high_score = high_score;
    }
    return high_score;
  }
}

score.saveHighScore(100)

window.console.log("Score: ", score.getHighScore());

I have no idea why, but I reloaded the same code posted above and it returns Score: 0 in the console.

它返回0的原因是在getHighScore内部，它从本地存储中检索值并比较它是否不是数字，如果不是数字您将其设置为0。由于本地存储将所有值保存为字符串，因此它始终将您的值设置为 0。

I'm not sure how the score function works, either

这些只是对象内部的函数。