if 循环中的条件以确保在数组中找到字符串

Question

使用从另一个函数随机生成的 3 个单词的数组，我试图获取一个函数来检查循环中的某个 i 单词（从图像文件的 src 给出）是否在从该其他函数生成的数组，如果不是 - 其他函数将再次运行，直到该单词包含在数组中。

var gFlavors = ['vanilla', 'chocolate', 'strawberry', 'lemon', 'peanutbutter']

function getFlavor(flavor) {
    var options = [];

    for (var i = 1; i <= gFlavors.length; i++) {
    // I have a folder of images, with the images named "1-vanilla.gif", "2-chocolate.gif" and so on. Using the loop, I am getting those images and setting a class and data for each
    flavor = new Image(150, 150);
    flavor.src = 'img/' + i + '-' + gFlavors[i - 1] + '.gif';
    flavor.setAttribute('class', 'flavor');
    flavor.setAttribute('data-flavor', gFlavors[i - 1]);
    var elFlavorsDiv.appendChild(flavor);

    // Slicing solely the flavor word found in each image filename
    var flavorImgSrc = flavor.attributes.src.nodeValue;
    var flavorImgSrcDash = flavorImgSrc.indexOf('-');
    var flavorStr = flavorImgSrc.slice(flavorImgSrcDash + 1, flavorImgSrc.length - 4);
    options = generateOptions();

    // The problematic line which doesn't do what I want it to: To check whether an i flavor is included in the generated random array (and if it isn't - re-generate the random array until the flavor is included) - For example: The generated random array is ['strawberry', 'peanutbutter', 'chocolate'] - if i is currently one of the 3 flavors found in the array, keep the array as it is, on the other hand if i is for example 'lemon' - re-run generateOptions() until the current i is found there - so I only get an array matching the current i
    if (!options[i].includes(flavorStr)) options = generateOptions();
}


// A function returning an array of 3 random flavors
function generateOptions() {
    var randomizedOptions = gFlavors;
    for (var i = 0; i < 3; i++) {
        shuffle(randomizedOptions);
        randomizedOptions.splice(0, randomizedOptions.length-3)
    }
    return randomizedOptions;
}

// A shuffle function for arrays
function shuffle(array) {
    array.sort(() => (Math.random() - 0.5));
}

预期结果示例： 生成的随机数组是 ['strawberry', 'peanutbutter', 'chocolate'] - 如果 i 当前是数组中找到的 3 种口味之一，则保持数组不变，另一方面，如果 i 是例如 ' lemon' - 重新运行 generateOptions() 直到在那里找到当前 i - 所以我只得到一个与当前 i 匹配的数组。

截至目前，我收到一个 TypeError: Cannot read properties of undefined (reading 'includes') at getFlavor

Answer 1

您的 generateOptions 函数返回 void。

因此options 是未定义的，这意味着options[i] 会抛出。