如何使用 javascript 插入和获取动态创建的输入字段的值？

Question

我正在根据单击的单选按钮动态创建输入，但我无法获取插入到输入字段中的值。我需要打印插入到同样动态创建的标签字段中的值。它看起来像这样：https://codepen.io/christmastrex/pen/jOmxmQY

因此，如果选择数字 4，则会创建 4 个输入字段，并且在第 3 列中，我需要打印输入字段中插入的值。

代码如下：

<div class="row">
    <div class="column">
        <h2>Column 1</h2>

        <div>
            <input type="radio" value="1" name="col1"><label for="1">1</label>
            <input type="radio" value="2" name="col1"><label for="2">2</label>
            <input type="radio" value="3" name="col1"><label for="3">3</label>
            <input type="radio" value="4" name="col1"><label for="4">4</label>
            <input type="radio" value="5" name="col1"><label for="5">5</label>
        </div>

        <button type="button">Add</button>
    </div>

    <div class="column" style="background-color:#ccc;">
        <h2>Column 2</h2>
        <div class="add-input"></div>
    </div>

    <div class="column">
        <h2>Column 3</h2>
        <div class="add-label"></div>
    </div>
</div>

.column {
    float: left;
    width: 30%;
    padding: 10px;
}

.row:after {
    content: "";
    display: table;
    clear: both;
}

#col2 {
    display: none;
}

var inputDiv = document.getElementsByClassName("add-input")[0];
var inputLabel = document.getElementsByClassName("add-label")[0];
var btn = document.querySelector('button[type="button"]');

btn.onclick = function () {
    var radioCheckedNum = document.querySelector('input[type="radio"]:checked')
    .value;

    for (let i = 0; i < radioCheckedNum; i++) {
        var inputFieldValue;
        inputDiv.innerHTML += `<input type="text" id="" value="" name="col2" onChange="${inputFieldValue}"><br><br>`;
        inputFieldValue = document.querySelector('input[name="col2"]').value;
        
        console.log(inputFieldValue);
        
        inputLabel.innerHTML += `<label>Label ${radioCheckedNum} - ${inputFieldValue}</label><br><br>`;
    }
};

Answer 1

请检查以下注释代码：

// GET ELEMENTS MORE EFFICIENTLY BY USING IDs.
const inputs = document.getElementById('add-input');
const labels = document.getElementById('add-label');
const button = document.getElementById('button');

const radios = document.querySelectorAll('input[type="radio"]');

// CREATE UTILITY FUNCTION TO CLEAR ALL CHILDREN FROM A NODE.
const clear = (node) => {
    while (node.firstChild) {
        node.removeChild(node.lastChild);
    }
};

const onClickHandler = () => {
    // CLEAR PREVIOUS ELEMENTS (REMOVE IF NOT NEEDED).
    clear(inputs);
    clear(labels);

    // GET CHECKED RADIO IN A MORE EFFICIENT WAY (WITHOUT QUERYING THE DOM AGAIN).
    const radio = Array.from(radios).find((input) => input.checked);

    // DO NOTHING IF NO RADIO IS CHECKED.
    if (!radio) {
        return;
    }

    // GET NUMBER OF INPUTS.
    const number = parseInt(radio.value);

    for (let i = 0; i < number; i++) {
        const index = i;

        /*
            NEVER USE 'innerHTML' BECAUSE IT IS NOT SAFE!
            INSTEAD, CREATE ELEMENTS PROGRAMMATICALLY USING DOM APIs AS FOLLOWS
         */
        const input = document.createElement('INPUT');
        const label = document.createElement('LABEL');

        // SET INPUT ATTRIBUTES.
        input.name = `${index}`;
        input.type = 'text';

        // ADD EVENT LISTENER TO EACH INPUT.
        input.addEventListener('input', ({target}) => {
            /*
                THIS CALLBACK WILL BE FIRED FOR EACH INPUT INDEPENDENTLY.
                HERE YOU CAN LEVERAGE 'label' REFERENCE TO CHANGE THE CORRESPONDING INNER TEXT.
             */
            label.innerText = `Label ${index} - "${target.value}"`;
        });

        // SET LABEL ATTRIBUTES.
        label.innerText = `Label ${index} - ""`;

        // ADD CREATED INPUT TO DOM AND SOME 'br' ELEMENTS.
        inputs.append(
            ...[
                input,
                document.createElement('BR'),
                document.createElement('BR')
            ]
        );

        // ADD CREATED LABEL TO DOM AND SOME 'br' ELEMENTS.
        labels.append(
            ...[
                label,
                document.createElement('BR'),
                document.createElement('BR')
            ]
        );
    }
};

// ADD EVENT LISTENER TO BUTTON USING THE NEWEST API (RECOMMENDED).
button.addEventListener('click', onClickHandler);

.column {
    float: left;
    width: 30%;
    padding: 10px;
}

.row:after {
    content: "";
    display: table;
    clear: both;
}

<div class="row">
    <div class="column">
        <h2>Column 1</h2>

        <div>
            <input type="radio" value="1" name="col1"><label for="1">1</label>
            <input type="radio" value="2" name="col1"><label for="2">2</label>
            <input type="radio" value="3" name="col1"><label for="3">3</label>
            <input type="radio" value="4" name="col1"><label for="4">4</label>
            <input type="radio" value="5" name="col1"><label for="5">5</label>
        </div>

        <button id="button">Add</button>
    </div>

    <div class="column" style="background-color:#ccc;">
        <h2>Column 2</h2>
        <div id="add-input"></div>
    </div>

    <div class="column">
        <h2>Column 3</h2>
        <div id="add-label"></div>
    </div>
</div>

如何使用 javascript 插入和获取动态创建的输入字段的值？

How to insert and get the value of a dynamically created input field using javascript?

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