要在JavaScript中设置线条的样式，请使用textDecorationStyle 属性。您可以为线条样式设置下划线，双线或上划线等。
您可以尝试运行以下代码以使用JavaScript在文本修饰中返回行的样式-
<!DOCTYPE html>
<html>
<body>
<div id = "myText" style = "text-decoration: underline;">
This is demo text.
</div>
<br>
<button onclick = "display()"> Set Text Decoration </button>
<script>
function display() {
document.getElementById("myText").style.textDecorationColor = "red";
document.getElementById("myText").style.textDecorationStyle = "double";
}
</script>
</body>
</html>