Question

披露：我是一个相当新的，没有经验的JS，但我花了几个小时试图通过Stackoverflow和其他互联网资源找到解决方案。我的导师本周离开了，所以我希望有人能帮到我。提前谢谢！

简介：我试图通过变量setupTotal跟踪正在运行的总计。我将它放在函数getStoredData的顶部，认为它会像全局一样，并且在getStoredData中的for循环期间不会被覆盖或重置。我已经将周围的代码包含在上下文中，并加粗了我认为与我所遇到的实际问题相关的内容。

问题：每次for循环循环迭代时，我的setupTotal变量都会被重置。我在控制台日志和buildSetup函数末尾的setupFees.innerHTML中都看到了这一点。根据我的理解，当我指定var setupTotal = 0;在getStoredData函数的开头，我在buildSetup嵌套函数中所做的更新应该覆盖原始值。然而，每次运行新迭代时，setupTotal值再次从0开始。

function getStoredData() {

    // Builds "Service Row" div to house the incoming content
    buildDivRow();

    var setupTotal = 0;

    // Loops through the boxes to see what's stored
    for (var service in serviceDatabase) {

        for (id=0; id < serviceDatabase[service].length; id++) {

        console.log("Starting " + service + ": " + serviceDatabase[service][id]);

            // Get the stored data if it exists
            var inputID = service + "-input-" + id;
            var getData = localStorage.getItem(inputID);
            console.log("Attempting data retrieval for " + inputID + ": " + getData);

            // Passes the info to a function that creates the HTML to display stored data
            if (getData != null) {

                // Passes the info to functions that captures "total" data
                console.log("buildSetup starting, service: " + service);
                console.log("buildSetup starting, getData: " + getData);
                console.log("buildSetup starting, setupTotal): " + setupTotal);
                buildSetup(service, getData, setupTotal);

                // Passes the info to a function that builds the div containers
                buildDivXs12(getData, inputID, service, id);

                // Logs that the data was found successfully or not
                console.log("Retrieved ID (" + inputID + ") and data (" + getData + ")");
            } else {
                console.log("No data to retrieve for " + serviceDatabase[service][id] + ": " + inputID );
            }
        }
    }
}

// Keeps track of the setup fees
function buildSetup(service, getData, setupTotal) {

    // Retrieve the setup fee
    var setup = setupDatabase[service][getData];
    console.log("buildSetup ending, setup: " + setup);

    // Update the setupTotal global var
    setupTotal = parseInt(setupTotal) + parseInt(setup);
    console.log("buildSetup ending, setupTotal): " + setupTotal);

    // Update the setupFees inner HTML
    var setupFees = document.getElementById("setupFee");
    setupFees.innerHTML = setupTotal;
}

Answer 1

根据您的代码，您可以做的是返回 buildSetup 函数上的 setupTotal 值，然后在 getStoredData 上调用后再分配它功能如下：

function getStoredData() {
  ..
  console.log("buildSetup starting, setupTotal): " + setupTotal);
  setupTotal = buildSetup(service, getData, setupTotal);
  ..
}

function buildSetup(service, getData, setupTotal) {
  ..
  setupFees.innerHTML = setupTotal;

  return setupTotal;
}

每次for循环迭代都会重置全局变量而不是更新

1 个答案: