js判断span是否为空

// 假设有一个id为'mySpan'的<span>元素
var span = document.getElementById('mySpan');

// 获取文本内容并去除首尾空白字符
var text = span.textContent.trim();

if (text === '') {
    console.log('span为空');
} else {
    console.log('span不为空，内容为：' + text);
}

var span = document.getElementById('mySpan');
var text = span.innerText.trim();

if (text === '') {
    console.log('span为空');
} else {
    console.log('span不为空，内容为：' + text);
}

var span = document.getElementById('mySpan');
var hasText = false;

for (var i = 0; i < span.childNodes.length; i++) {
    var node = span.childNodes[i];
    if (node.nodeType === Node.TEXT_NODE && node.nodeValue.trim() !== '') {
        hasText = true;
        break;
    }
}

if (hasText) {
    console.log('span不为空');
} else {
    console.log('span为空');
}