如何遍历对象数组并将结果显示在列表中？

Question

我正在尝试从一组联系人中创建一个无序列表。

数组类似于：

let contacts = [{firstName:"John", lastName:"Doe", age:46}, {firstName:"Mike", lastName:"Smith", age:46}, {firstName:"Joe", lastName:"Dirt", age:46}];

我可以像这样从一个基本数组创建一个列表：

var options = [
        set0 = ['Option 1','Option 2'],
    ];

function makeUL(array) {
    // Create the list element:
    var list = document.createElement('ul');

    for(var i = 0; i < array.length; i++) {
        // Create the list item:
        var item = document.createElement('li');

        // Set its contents:
        item.appendChild(document.createTextNode(array[i]));

        // Add it to the list:
        list.appendChild(item);
    }

    // Finally, return the constructed list:
    return list;
}

// Add the contents of options[0] to #foo:
document.getElementById('foo').appendChild(makeUL(options[0]));

我不太明白如何使用对象制作列表。

Answer 1

在 JavaScript 中，对象可以使用 .或 []。

例如）array[i].firstName 或 array[i]['firstName']

您可以使用模板字符串或 JSON.stringify

const item = array[i];

item.appendChild(document.createTextNode(`firstName: ${item.firstName}, lastName: ${item.lastName}`));

或

item.appendChild(document.createTextNode(JSON.stringify(array[i]));

Answer 2

let contacts = [
    {firstName:"John", lastName:"Doe", age:46}, 
    {firstName:"Mike", lastName:"Smith", age:46}, 
    {firstName:"Joe", lastName:"Dirt", age:46}
];

function makeUL(array) {
    // Create the list element:
    var list = document.createElement('ul');

    for(var i = 0; i < array.length; i++) {
        // Create the list item:
        var item = document.createElement('li');

        // Set its contents:
        item.appendChild(document.createTextNode(array[i].firstName + ' ' + array[i].lastName + ' ' + array[i].age));

        // Add it to the list:
        list.appendChild(item);
    }

    // Finally, return the constructed list:
    return list;

}

document.getElementById('foo').appendChild(makeUL(contacts));

按照 tyler 的建议，我将在解决方案中添加一些上下文。我复制了相同的功能，然后就使用了 .访问对象的内容。

Answer 3

我刚刚在浏览器控制台中对此进行了测试。不知道你在找什么，但如果你有一个对象数组并想从中创建一个 ul 列表，你可以尝试这样的事情：

var options = [{firstName:"John", lastName:"Doe", age:46}, {firstName:"Mike", lastName:"Smith", age:46}, {firstName:"Joe",姓氏：“污垢”，年龄：46}];

function makeUL(array) {
    // Create the list element:
    var list = document.createElement('ul');

    for(var i = 0; i < array.length; i++) {
        // Create the list item:
        var item = document.createElement('li');
        for (var key in array[i])
        // Set its contents:
        item.appendChild(document.createTextNode(array[i][key] + " "));

        // Add it to the list:
        list.appendChild(item);
    }

    // Finally, return the constructed list:
    return list;
}

// Add the contents of options[0] to #foo:

alert(makeUL(options).outerHTML);

这会给你这样的东西：

<ul><li>John Doe 46 </li><li>Mike Smith 46 </li><li>Joe Dirt 46 </li></ul>

你可以修改它以满足你的需要。

这是另一个变体：

var options = [{firstName:"John", lastName:"Doe", age:46}, {firstName:"Mike", lastName:"Smith", age:46}, {firstName:"Joe", lastName:"Dirt", age:46}];

function makeUL(array) {
    // Create the list element:
    var list = document.createElement('ul');

    for(var i = 0; i < array.length; i++) {
        // Create the list item:
        var item = document.createElement('li');
        var text = new Array();
        for (var key in array[i]) {
        // Set its contents:
        text.push(array[i][key]);
        }
        item.appendChild(document.createTextNode(text.join(",")));
        // Add it to the list:
        list.appendChild(item);
    }

    // Finally, return the constructed list:
    return list;
}

// Add the contents of options[0] to #foo:

alert(makeUL(options).outerHTML);