javascript - 删除我的本地存储

Question

有了以下本地存储脚本，我正在寻找一种方法，以便在 7 天后，如果余额 = 0，余额将被重置。我应该怎么做？

var balance = localStorage.getItem('balance');

if (balance === null) {
    // Not found, set value from database or wherever you get the value
    balance = 50; // Or whatever value
} else {
    // Convert the retrieved value to a number, since
    // localStorage stores everything as string.
    balance = +balance; 
}

function updateBalance(newBalance) {
        localStorage.setItem('balance', newBalance);
        balance = newBalance;
    }

Answer 1

您需要将日期与余额一起存储。由于 localStorage 仅存储字符串，因此您可以使用 JSON 将余额 + 日期对象转换为字符串。像这样的事情:

var balanceObj = {
    balance: 0,
    transactionDate: new Date()
};

存储它:

localStorage.balance = JSON.stringify( balanceObj );

检索它:

balanceObj = JSON.parse( localStorage.balance );